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No. 0102
Model C1422R C1422T C2122T CP1422R CP2122R CP1422T CP2022T CP2122T CP1422T-481 CP2122T-481 CP1422T-491 CP2022T-491 CP2122T-491 CS1422R CS2022R CS2122R CL1422R CL2122R Chassis F1R F1Y F4Y F1GR F4GR F1GY F2GY F4GY F1HY F4HY F1HY F2HY F4HY F1KR F2KR F4KR F1FR F4FR

SERVICE MANUAL MANUEL D'ENTRETIEN WARTUNGSHANDBUCH CAUTION:

Before servicing this chassis, it is important that the service technician read the "Safety Precautions" and "Product Safety Notices" in this service manual.

Avant d'effectuer l'entretien du châassis, le technicien doit lire les «Précautions de sécurité» et les «Notices de sécurité du produit» présentés dans le présent manuel.

ATTENTION:

VORSICHT:

Vor Öffnen des Gehäuses hat der Service-Ingenieur die ,,Sicherheitshinweise" und ,,Hinweise zur Produktsicherheit" in diesem Wartungshandbuch zu lesen.

Data contained within this Service manual is subject to alteration for improvement. Les données fournies dans le présent manuel d'entretien peuvent faire l'objet de modifications en vue de perfectionner le produit. Die in diesem Wartungshandbuch enthaltenen Spezifikationen können sich zwecks Verbesserungen ändern.

TECHNICAL SPECIFICATIONS
TV Standard ....................................... 625 lines, STANDARD I (UK) B/G/H/DK, L/L', (Export) Channel coverage..............UHF Channels (UK) UHF/VHF Hyper band (Export) Aerial input impedance .......................... 75ohm Unbalanced Power Consumption ..................... Picture Tube 14" Models < 40W 35.5cm types 20" Models < 48W 48cm types 21" Models < 52W 51cm types Consumption in standby mode................. <4W Mains Voltage ........................220V/210V, 50Hz Fuse..........................................2 Amp time-lag

SPÉCIFICATIONS TECHNIQUES
Standard TV .....................................625 lignes, STANDARD: R-U B/G/H/DK, L/L': (Export) Couverture de canaux......... Canaux UHF (R-U) UHF/VHF Band hyper (Export) Impédance d'entrée d'antenne............ 75 ohms Non équilibrée Consommation électrique.......... Tubes-images 14" Models < 40W 35.5cm types 20" Models < 48W 48cm types 21" Models < 52W 51cm types Consommation en mode veille ................. <4W Tention secteur ......................220V/240V, 50Hz Fusible ......................................2 Amp time-lag

SPECIFICATIONS TECHNIQUES
Fernsehnorm....................................625 Zeilen, Fernsehnorm I (nur GB) Fernsehnorm B/G/H/DK, L/L' (Export) Kanäle.................................. UHF-Bereich (GB) UHF/VHF/Hyperband Bereich Antenneneingangsimpedanz .............. 75 ohms Unsymmetrisch Leistungsaufnahme ............................Bildröhre 14" Models < 40W 35.5cm types 20" Models < 48W 48cm types 21" Models < 52W 51cm types Leistungsaufnahme im standby mode......<4W Netzspannung .........................220/240V, 50Hz Sicherung..................................2 Amp time-lag

December 1998

2

ENGLISH
SAFETY PRECAUTIONS
WARNING: The following precautions must be observed.

ALL PRODUCTS
Before any service is performed on the chassis an isolation transformer should be inserted between the power line and the product. 1. When replacing the chassis in the cabinet, ensure all the protective devices are put back in place. 2. When service is required, observe the original lead dressing. Extra precaution should be taken to ensure correct lead dressing in any high voltage circuitry area. 3. Many electrical and mechanical parts in HITACHI products have special safety related characteristics. These characteristics are often not evident from visual inspection, nor can the protection afforded by them necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified by marking with a ! on the schematics and the replacement parts list. The use of a substitute replacement component that does not have the same safety characteristics as the HITACHI recommended replacement one, shown in the parts list, may create electrical shock, fire, X-radiation, or other hazards. 4. Always replace original spacers and maintain lead lengths. Furthermore, where a short circuit has occurred, replace those components that indicate evidence of overheating. 5. Insulation resistance should not be less than 2M ohms at 500V DC between the main poles and any accessible metal parts. 6. No flashover or breakdown should occur during the dielectric strength test, applying 3kV AC or 4.25kV DC for two seconds between the main poles and accessible metal parts. 7. Before returning a serviced product to the customer, the service technician must thoroughly test the unit to be certain that it is completely safe to operate without danger of electrical shock. The service technician must make sure that no protective device built into the instrument by the manufacturer has become defective, or inadvertently damaged during servicing.

CE MARK
1. HITACHI products may contain the CE mark on the rating plate indicating that the product contains parts that have been specifically approved to provide electromagnetic compatibility to designated levels. When replacing any part in this product, please use only the correct part itemised in the parts list to ensure this standard is maintained, and take care to replace lead dressing to its original state, as this can have a bearing on the electromagnetic radiation/immunity.

2.

PICTURE TUBE
1. The line output stage can develop voltages in excess of 25kV; if the E.H.T. cap is required to be removed, discharge the anode to chassis via a high value resistor, prior to its removal from the picture tube. High voltage should always be kept at the rated value of the chassis and no higher. Operating at higher voltages may cause a failure of the picture tube or high voltage supply, and also, under certain circumstances could produce X-radiation levels moderately in excess of design levels. The high voltage must not, under any circumstances, exceed 29kV on the chassis (except for projection Televisions). The primary source of X-radiation in the product is the picture tube. The picture tube utilised for the above mentioned function in this chassis is specially constructed to limit X-radiation. For continued X-radiation protection, replace tube with the same type as the original HITACHI approved type Keep the picture tube away from the body while handling. Do not install, remove, or handle the picture tube in any manner unless shatterproof goggles are worn. People not so equipped should be kept away while picture tubes are handled

2.

3.

4.

LASERS
If the product contains a laser avoid direct exposure to the beam when the cover is open or when interlocks are defeated or have failed.

3

SAFETY AND ISOLATION
1. 2. 3. 4. Under no circumstances should any form of repair or maintenance be attempted by any person other than a competent technician or engineer. The following precautions should be observed: For purposes of servicing, the chassis should be supplied from an isolation transformer of at least 150W rating. If disturbed, the original lead dressing should be restored. This is particularly important due to the 'hot coil' nature of the chassis. Lead dressing will also have a bearing on the EMC performance of the chassis. Components marked ! on the circuit diagram are safety approved types and have special safety related characteristics. Only the manufacturers replacement components should be used. Replacement with alternative or 'up-rated' parts e.g. higher power resistors definitely does not guarantee the same level of protection and may create a fire, electric shock or X-radiation hazard. Components not bearing the ! mark should still be replaced with the originally fitted type and should be mounted in the same way.

5.

The Isolation Barrier
The chassis is a 'hot-coil' chassis whereby the line deflection coils are NOT isolated from the mains since the PSU does not provide B+ rail isolation. Consequently, the mains isolation barrier is more convoluted than in a conventional chassis and a much larger portion of the chassis is non-isolated. Figure 1 shows the isolation barrier position in the chassis.

It can be seen that both the DST (T401) and the scan coils now straddle the isolation barrier and are, as such, safety critical components. Also, the opto-coupler (I402) is required to pass line drive from I501 on the 'cold' side to the line drive stage on the 'hot' side. The isolation barrier therefore consists of T802, T401, I402, C804, R804, R805, the scan coils and 6mm air gaps. To maintain barrier integrity care should be taken not to reduce any air gaps, e.g. by protruding wires, following component replacement. Deflection yoke lead dressing is important to maintain double insulation across the isolation barrier. The position of the deflection lead sleeving is maintained by a tie wrap. Should this be removed for any reason, the sleeving should be slid towards the deflection yoke and tie wrapped into position.

Semiconductor Device Handling Precautions
The chassis contains devices which may be damaged by static electrical charge during handling, particularly I501, I602, I701 and Q801. To avoid damage, soldering irons should be earthed and service engineers should ideally wear wrist straps earthed through a 1M resistor or at least discharge themselves to an earthed point. 4

SERVICING
Microprocessor Control System
Microcontroller
Micro-controller, I701, is either a SAA5288 (on non-teletext sets) or a SAA5290 (on teletext sets). Both devices have integrated on-screen display (OSD) generator; the SAA5290 also has an integrated teletext decoder. The micro-controller has a single 12MHz crystal X701. The television is controlled by serial (I˛C) bus communication, digital switching inputs and outputs, analogueto-digital inputs and pulse-width-modulation (PWM) outputs.

Reset
At power on, C709 is not charged so the voltage on pin 43 of the micro-controller rises with the 5V supply and resets the micro-controller. An internal resistor to ground at this pin causes C709 to charge up and the voltage on the reset pin to drop to 0V. In normal operation, transistor Q702 is switched on and the reset pin is low, but if the 10V supply voltage drops below about 8V the transistor will switch off and R721 will pull the reset pin high and reset the device.

User Control
User input is via infra-red remote control (Philips' RC5 protocol), internally decoded from the receiver I703, or from three (non-matrixed) local control keys on active low inputs, I701 pins 18, 19 and 20. The LED flashes each time a key is detected or remote command received.

Tuning
The tuning control voltage to the tuner is controlled via the PWM at pin 1 of I701 and integrating circuit around Q001. Minimum voltage is at maximum mark-space ratio (bottom of each band). Band-switching is controlled by active low outputs on pins 14, 15 and 16 (high, mid, low) and transistors Q002 to Q004. The controller makes AFC corrections by reading on-tune information from I501 via the I˛C bus. As the tuner is controlled by voltage synthesis, there is no direct correlation between the controller output and the tuned frequency.

Non-volatile memory
The non-volatile memory, I702, holds configuration information, user settings, parameters as applicable for I˛C controlled ICs and the programme tuning records. It is itself accessed by I˛C. When a new memory IC is fitted, the microcontroller will automatically load default information, which takes a few seconds during power-up. Regular re-loading of the data, or corruption of settings may indicate I702 is faulty.

AV switching
Inputs from pins 8 and 16 of SCART 1 are sampled by analogue to digital conversion on pins 9 and 10 of I701 respectively. The input levels are adjusted such that the controller will automatically switch to AV1 when pin 8 is above 6V and RGB when pin 16 is above 1V. The time constant on pin 16 ensures the controller will not detect real-time RGB insertion using pin 16.

OSD / Teletext
Line and field timings are obtained from V.sync on pin 37 and H.sync input on pin 36. Teletext (on teletext sets only) is obtained from the CVBS input on pin 23. The RGB outputs on pins 34, 33 and 32 respectively are inserted into the TV output when gated by the OSD EN OUT signal on pin 35. OSD / teletext contrast is controlled by the peak reference level on pin 31, generated from the microcontroller PWM output on pin 2 via Q305.

Error codes
Under the following fault conditions the television will switch to standby and flash the LED. 5

Fault Condition Multiple TDA884X I˛C errors Line start-up sequence failed Black current (BC) loop unstable Vertical scan failure

No. of Flashes 1 3 4 5

Over voltage / X-ray protection (OVP) 2

Continuous TDA884X power-on reset 6 Multiple error codes may appear, eg. two quick flashes, pause, four quick flashes etc. for OVP + BC loop errors.

Adjustments
In order to make service adjustments including setting the height, width, various configuration options, etc., the TV should have a suitable signal tuned in; ideally, a geometry test card. A teletext signal is recommended for setting OSD contrast on a teletext chassis. To enter service mode, place a shorting link across terminals 2 and 3 of P701. In service mode, two 2-digit hexadecimal numbers are displayed to the left of the screen; the lefthand one is the service parameter number, the righthand one is the value for that parameter. Some parameters are identified by a two-letter code instead of a number, see below. For example:- 0A 1F shows parameter ten (0A hex) at thirty-one (1F hex). In this mode of operation some of the remote control keys have different functions; The up and down and local select keys are used to select a parameter. The remote and local left and right keys are used to change the value of the current parameter. The TV button is used to store any changes. The teletext select and digit '0' keys are used for programme up or down. The Normalize key selects factory picture settings immediately over-writing user settings. The digit keys '1', '2',----'8' toggle the state of the individual bits '7', '6',----'0' of the value of the current parameter, for example, pressing digit key '4' would change value 1F hex to 0F hex. TO STORE THE CHANGES, PRESS THE TV KEY ON THE HAND UNIT BEFORE REMOVING THE SERVICE MODE LINK. THE MESSAGE 'STORED' WILL BE DISPLAYED TO CONFIRM THE OPERATION. Under certain circumstances, for example abnormal operation due to suspected corruption of the service parameters, it may be necessary to perform a complete reset of the non-volatile memory (I702). To effect this, press and hold the X (teletext update) key for about 3 seconds or until the set switches to standby. Following this it will be necessary to perform a 'set-up' of the television.

Service Parameters
The following values assume you are watching a tuned in picture, on RF. (On other sources, or with no signal, some values may differ.) Service parameters 00 to 1A apply to the control registers of I501 as shown in the following table. No. 00 01 02 03 04-07 08 09 0A Value 14" 20" 21" 02 D0 1F 20 00 20 10 44 02 D0 1F 1D 00 1F 0B 4A 02 D0 1F 27 00 1E 1A 4A System Control System Control Horizontal shift E-W control Vertical slope (linearity) Height S-correction 6 Do not adjust Do not adjust Adjust to centre picture horizontally Not used on this chassis Adjust for vertical linearity Adjust for correct picture height Adjust for best vertical S-correction Function Action

Hue (SCART NTSC 4.43 playback only) Use picture menu control instead

No. 0B 0C 0D 0E 0F 10 11 12 13 14 15 16 17 18 19 1A

Value 14" 20" 21" 2B 29 29 29 1C 5C 9C 1C 13 0A 50 19 20 81 08 00 1B 38 38 38 1C 5C 9C 1C 13 0A 50 19 20 81 08 00 1B 3D 3D 3D 1C 5C 9C 1C 13 0A 50 19 20 81 08 00

Function Vertical shift White point - Red White point - Green White point - Blue Peaking (sharpness) Brightness Saturation Contrast AGC take-over point Volume IF PLL adjustment Vertical zoom Vertical scroll Control 2 Control 3 Control 4

Action Adjust to centre picture vertically See "Adjustments" in Servicing Use picture menu control instead Use picture menu control instead Use picture menu control instead Use picture menu control instead See "Adjustments" in Servicing Set to 50 hex Not used on this chassis Not used on this chassis Do not adjust Do not adjust Do not adjust

Service Parameter Functions
Parameters above 1A are designated by two-letter codes (except text contrast on a teletext set). These control configuration. Text Mode Text (OSD) contrast Set as preferred, see notes below Ex Export (VHF/UHF) setting 00 for UHF-only, 01 if multi-band tuner AV AV socket configuration 00 single SCART, 01 single SCART plus phono inputs It is advisable to make a note of the existing values prior to commencing servicing. (see "Adjustments" in Servicing)

7

Adjustments
H. T. Setting
The HT should be adjusted using R818 to obtain correct width with normal brightness and contrast settings. A Philips complex test pattern is ideal for the operation.

A1 Control
This should be set using the `screen' control on T401 to achieve 140V black level at the tube base cathodes with the brightness and contrast settings normalized. In practice the black level of the individual guns will differ and are set by I501 to achieve equal cut-off points.

White Points
These should be adjusted via service parameters 0C, 0D and CE whilst viewing a picture with little light area to prevent beam current limiting. The parameters should be adjusted for a black to white swing of 50V ±1V (14"), 55V ±1V (20") or 60V ±1V (21") on each of the three cathodes with the picture normalized.

Text Contrast
White balancing of the red and blue outputs, relative to the green, should be carried out to ensure pure white text, using RV317 (R) and RV319 (B). As the picture outputs are automatically balanced, text white may be set using picture white as a reference once the black and white points (See adjustments section) have been set. The text contrast itself should be adjusted such, that the Text/OSD white parts are approximately 75% of the intensity of a test pattern peak white area: this corresponds to the 75% grey blocks in part of a `Philips 5544' type test pattern. When the text contrast service parameter is selected the TV switches to teletext mix mode, page 101. If no text is present P100 will still appear in the top left corner of the screen together with some text on the bottom row of the display. There is no on-screen parameter: adjust with volume control as normal and change parameter with programme up/down keys.

AGC
The AGC take-over point should be adjusted via service parameter 13 such, that the tuner output to the SAW filter is 600mV pk-pk (300mV per side for symmetrical tuner output) using a test pattern with no sound carrier.

Focus
Adjust the upper control on the rear of the flyback transformer for best focus.

Positioning
Horizontal position should be adjusted via service parameter 03 so as to centre the picture. Vertical position should be adjusted via service parameter 0B so as to centre the picture. This may be simplified by pressing `1' with service parameter 0B selected to activate service blanking which blanks the lower half of the picture. The edge of the blanked area may then be aligned with the tube centre marks. Service blanking is disabled by once again pressing the `1' key.

Linearity
Horizontal linearity is fixed; no adjustment is possible. Vertical linearity is adjusted using service parameters 08 and 0A (linearity and S-correction) whilst displaying a cross hatch pattern. Adjust the linearity for evenly spaced intervals at the top and bottom of the picture, then adjust the S-correction to achieve equal spacing accross the whole screen.

Vertical Protection Disable
Vertical protection is used to shut down the chassis in the event of field-scan failure. For diagnostic purposes this can be disabled by selecting service parameter OA (S-correction) and pressing the number 2 key on the 8

hand unit. After repair, vertical protection should always be re-enabled by pressing the number 2 key again and storing it with the TV key. (The value of parameter OA toggles between two values when the number 2 key is pressed, the higher of which indicates that the vertical protection is enabled.).

Auto Black Level Disable
I501 independently sets the black level of each CRT gun to equalize the cut-off points and therefore provide a true black. For diagnostic purposes this control loop may be disabled by selecting service parameter 02 (hue) and pressing the number 2 key on the hand unit. After repair, the auto black level sampling should always be re-enabled by pressing the number 2 key again and storing it with the TV key. (The value of parameter 02 toggles between two values when the number 2 key is pressed, the lower of which indicates black level sampling is enabled).

Adjustment Locations (Physical)
See adjustment locations PCB

9

CIRCUIT DESCRIPTION
Switched Mode Power Supply
Summary
The power supply is a self-oscillating discontinuous buck converter (step-down chopper) under peak current control and designed for up to 65W output power at nominally 98V. The main B+ output of this converter topology is inherently non-isolated and as such, output voltage feedback does not require an opto-coupler. Some energy is derived in flyback mode via an isolated winding on the buck inductor to provide a low power 10V secondary supply from which are derived switched 8V (video processor) and permanent 5V (µP) supplies. In stand-by mode, both the B+ and 10V supplies remain close to their nominal operating levels but with virtually zero load, the PSU enters a burst-mode whereby typically 180 in 200 cycles are skipped. In this way, the stand-by power consumption (including degaussing circuit) is less than 4W.

Description of Operation of the Buck Converter
Figure 4 shows the main components of the buck converter. The output voltage may be controlled between zero and the input voltage by varying the on-time of Q801. During this period, Vin-Vout is applied across the buck inductor (T802 winding pins 7 & 8) and the current in it ramps up linearly. When Q801 is turned off, Vout is applied across the buck inductor and energy is delivered to the load and C809 combination.
280 - 390 T802 (pins 7 & 8)

Q801 VIN D804 C809 VOUT (100V)

Start-Up

Fig 4

The Buck Converter Topology

At start-up, the overwind output voltage (T802 winding pins 7 & 8) is not present so a start-up bias circuit is required. This consists of R806, D802 and R809. Approximately 16V is produced at the junction of R806 and D802 which is fed via R809 to turn on Q801 for the first time.

Control Method
During the on-time of Q801, the buck inductor voltage flows through the current sense resistor R814 forming an analogue of the buck inductor current. This is fed to the base of Q802 along with a DC bias current from the error amplifier (via R813) such that once a certain buck inductor current level is reached, Q802 turns on. When this happens Q801 is turned off and the inductor current free-wheels through D804. This is peak current-mode control.

Output Voltage Regulation
The non-isolated B+ rail means that no opto-isolator is required for direct Vo control. It can be seen from Figure 5 that Vo minus a small zener voltage drives the emitter of this transistor (Vo-Vz) whilst a resistive potential divider feeds the base (kVo, k<1). If, for instance, the output voltage tends to rise, Ve rises by Vo whereas Vb only rises by kVo. The net result is an increase in negative bias and an increase in collector (control) current. R818 in the potential divider provides an element of control over the B+ voltage. 10
Vz D806 Ve Vb R815

R817 R818 kVo R820 Control Current

Fig 5

The Error Amplifier

Overvoltage Protection
An unfortunate characteristic of the buck converter is that if the power switch Q801 should become shortcircuit, the full rectified mains voltage appears at the output, over stressing components in both the PSU itself and the load. In order to limit the output voltage rise under these conditions, a 130V 5W zener diode D805 is fitted across the B+ output. An over-voltage causes conduction of D805, shorting the B+ output and blowing the fuse F801.

Isolated Supplies
In order to provide low voltage isolated supplies, a secondary winding is included on the buck inductor, phased such that energy is delivered in flyback mode, that is when Q801 is off. During this interval, the buck inductor voltage is clamped to the output voltage and the turns ratio is chosen to provide a secondary of 10V with rectification and smoothing performed by D807 and C812 and overload protection by R821. A permanent 5V µP supply is derived from this 10V supply by I801 as well as an 8V switched supply under µP control by Q804, R822, D808 and Q805.

Chassis Start-Up Procedure
The PSU topology used in the chassis has a characteristic which complicates start-up. Until a B+ load is established (i.e. the line output stage starts), the isolated secondaries are very high impedance - simply turning on the video processor 8V supply and waiting for line-drive to start-up would fail since the supply cannot deliver I501's supply current. In order to overcome this problem, a system of 'pseudo line-drive' was devised which allows the line output stage to be driven by the µP in order to establish a B+ load prior to turnon of the video processor 8V supply. Figure 6 is a block representation of this system.
8V 10V from PSU

8V I402

Q804, R822, D808, Q805

12, 37

48 8V Control 7 Pseudo Line Drive

I501
HOUT

Q402, R423 True 40 Line

Q406, R427

I701
Q405, R422 30 True Line Drive Gating

47

Fig 6 Start-up Circuit Block Diagram

True Line Drive Detection

The two line drive sources are OR-ed together at the input of I402, the two driver transistors being Q402 and Q406. The µP is responsible for ensuring that both line drive sources cannot drive the output stage simultaneously and to achieve this, the true line drive from I501 is monitored (µP pin 47). In this way, the transition from pseudo to true line-drive is timed to the latter starting up. However, the line-drive stage does not reliably operate at 31kHz so the soft-start cycle of I501 must be gated out. The µP achieves this by keeping Q405 on for a fixed time after true line-drive has been detected thus keeping Q402 off. When this time has elapsed, pseudo line-drive is stopped and Q405 turned off simultaneously, completing the start-up sequence. On reverting to stand-by pin 7 reverts to the high state which maintains I402 in conduction via Q406. This maintains Q403 on and the line output transistor (Q404) off.

11

Tuner and IF Stages
Tuner
The main chassis is fitted with a voltage synthesis UHF tuner for system I. Control of the tuned frequency is achieved by a voltage on pin 2 of the tuner. This voltage is derived from integrating a 33 volt PWM switched waveform. This PWM waveform is derived from pin 1 of the microcontroller I701. The AFC is sampled by the microcontroller via the I˛C bus from I501 and frequency correction is achieved by microcontroller adjustment of the duty cycle of the PWM which then modifies the tuner frequency.

AGC Adjustment
For most aerial input signal levels the tuner operates at maximum gain. At high signal levels the gain of the tuner is reduced by an AGC voltage generated in the IF stage. The AGC output from the IF (pin 54 of I501) is applied to pin 1 of the tuner (H001). The AGC maintains a maximum IF voltage of 600mV peak to peak. The voltage level can be adjusted using the following procedure: Short circuit pins 2 and 3 of P701 to enter service mode. When in service mode use the programme up and down keys to select service parameter 13. Using a 40MHz or greater oscilloscope, monitor pin 11 of TU001. Adjust service parameter 13 using the volume up and down keys for 600mV on pin 11 for a single ended tuner, and 300mV for a differential output tuner. Press the RV key to store the AGC value.

AFC Adjustment
The AFC voltage is not available at any point on the chassis; it is read by the microcontroller via the I˛C bus. Therefore, one of the following methods can be used to correctly align the AFC. a) For demodulator tank coil fitted (I501 = TDA884X Mask 1) Tune a known channel. Using a spectrum analyzer monitor pin 11 of H001. Fine tune the tuner for a carrier frequency of 38.9MHz. Store the fine tuned frequency (i.e. AFC off). Enter service mode by applying a short circuit to pins 2 and 3 of P701. When in service mode use the programme up and down keys to select service parameter 15. Adjust service parameter 15 using the volume up and down keys until the two bits at the top right of the screen meet the following criteria: Left hand bit permanently set. Right hand bit toggles (either 1 to 0 or 0 to 1). When the AFC value has been set press the TV key to store it. b) For demodulator tank coil not fitted (I501 = TDA886X Mask 2) Adjust service parameter 15 using the volume up and down keys until its value is 50. When the AFC value has been set press the TV key to store it.

Vision Decoding
The majority of the vision and sound, deflection and colour decoding is performed by I501. The IF signal passes from the tuner through the SAW filter (X001) to filter unwanted frequencies to I501. It is demodulated internally and the output at pin 6 is buffered by Q501. The sound and vision components are now separated. Z501 removes the sound from the vision components and Z601/602 filters the FM sound to pin 1 for demodulation. Video is then fed to the SCART socket output, pin 19 of P501 via Q502.

12

Source Selection
Source selection is controlled by the microcontroller via I˛C bus commands. The video processor I501 can select between internal demodulated CVBS video on its pin 13, external CVBS video (AV1) from pin 20 of P501 on its pin 17 or, if available, from external CVBS video (AV2) from the yellow phono socket of PA501, which is applied to pin 11. The internally demodulated CVBS video is always available on pin 19 of P501. External RGB is selected within I501. Fast blanking pulses from pin 16 of P501 are passed via an OR-ing circuit of Q301-304 and associated components to pin 26 of I501. This pin controls the state of the RGB outputs to the tube base pins 19, 20 and 21. It has three possible states: 1) 2) 3) Less than 0.4V Between 0.4V and 4.0V Greater than 4V Internal RGB from colour decoder. External RGB from pins 7, 11 and 15. Output blanked for OSD/Text insertion.

When teletext or OSD is displayed, pin 35 of I703 goes from ground to 5.0 Volts. This signal is passed via Q301 and causes pin 26 of I501 to enter the third state above, independent of the state of the other inputs to the OR circuit. During mixed TV/Text mode or whilst the OSD is showing on part of the screen this line will be switching at a high rate. RGB mode can be selected manually by the user and in this case the open-drain output on pin 8 of the micro-controller will be switched off and will be pulled up to 1.7 volts by R307 and R306. Q302 then applies a voltage of about 1.0 volts to pin 26 of I501. In the absence of a higher voltage via Q301 and Q303 from the fast blanking input, pin 16 of P501, this is still sufficient to enter the external RGB mode. Audio source switching is controlled via the microprocessor I701. The audio is switched from internal to external source via I˛C in I501. Internal source is fed to I501 at pin 1 and the external source at pin 2. On models equipped with front AV, the external source is provided either from pins 2 and 6 of P501 or the white phono socket PA501.The external source selection is controlled by pin 3 of I701 and Q703, then switched by I602. On models without front AV, I602 is omitted and bypassed via R601. On models equipped with a headphone socket, the speaker feed from the audio amplifier (I601) is diverted to the headphone when a headphone jack is plugged into PA601.

13

Colour Decoder
The luma signal processing and colour decoding are implemented by I501. The luminance and chrominance signals are separated internally. A delay line is also incorporated to compensate for the difference between the luma and chroma processing times. There are no adjustments required on the colour decoder.

On-Screen Display
The micro-controller on-screen display (OSD) supplies blanking and RGB signals for overlaying the television picture. Pin 35 of I701 provides blanking pulses which are applied to pin 26 of I501 via Q301, to turn off the decoder RGB output so that the OSD is clearly visible. The RGB signals from pins 34, 33 and 32 of I701 are applied directly to the tube-base via Q306 to Q308 and the text drive colour balance presents R317 and R319.

14

Horizontal and Vertical Deflection
In addition to decoding and switching, I501 provides deflection processing for the horizontal and vertical time-base circuits. Using video from the IF or external source as appropriate, the timebase circuit of I501 produces horizontal drive pulses at pin 40 to switch horizontal drive transistor Q402, and a differential vertical ramp at pins 46 and 47 to drive the vertical deflection output amplifier (I401). All geometry adjustments are performed via the I˛C bus with the service parameters (See adjustments section) with the exceptions of picture width (which is fine tuned by adjusting the B+ voltage by means of R818) and horizontal linearity (which is fixed by L402.)

Line Circuit
The primary side of the line circuit and the deflection coil are connected to the hot earth. The driver circuit contains an opto-coupler to create isolation between the low signal parts and the mains. The opto-coupler is driven by pin 40 of I501 via transistor Q402. When Q402 is not conducting, the LED of the opto-coupler is also out of conduction, and Q403 is also not conducting. In this way, Q404 will conduct and the B+ voltage (100V) is placed across winding 2-1 of the line output transformer (T401). A voltage across winding 2-1 of the line output transformer (T401) will cause a voltage across the windings 6- 9, 7- 9, 8- 9 and 10- 9. Energy is now transformed from the primary to the secondary side and charges capacitors C407 (+200V video supply), C408 (+13V field supply) and C409 (13V field supply). When transistor Q402 conducts, the LED of the opto-coupler is activated. This causes the transistor of the opto-coupler to conduct, which drives Q403 into conduction. This brings Q404 out of conduction. Due to this configuration, this circuit is protected against missing line-drive pulses. When a line-drive pulse is missed, the line output transistor (Q404) stays out of conduction, because the LED of the opto-coupler is forced into conduction by Q402 and R405 and R406. By this means, damage is avoided when there is no line drive. The line output transistor Q404 is helped in its switching action by the extra winding 2-3 while C412 helps in the switching action and prevents Q404 overheating. C418 prevents Q404 from switching at twice line frequency. Line jitter is reduced by capacitor C417 in the collector of Q402. On the secondary side of the line output transformer (T401) there is a blanking circuit which consists of C749 and R734, D501, D502 and D503. As Q404 switches off this circuit sends a pulse to pin 41 of I501 via R532 to blank the picture.

Horizontal Deflection
The voltage across capacitor C809 is the same as the voltage between B+ and the hot earth. (100V) When Q404 is conducting, this voltage is placed across the horizontal deflection coil via C411 and L402. This causes a linearly increasing current through this coil, thus creating horizontal deflection. When Q404 switches off, horizontal flyback takes place and then horizontal deflection is repeated and so on. C411 and L402 are used for linearity correction.

Vertical Deflection
Vertical deflection is based on a balanced input amplifier I401 connected to the +13V supply and -13V supply. This is driven from pins 46 and 47 of I501 via R407 and R408. A negative going ramp at field rate from I501 pin 46 is used to control I401. When the ramp is at its highest point, vertical flyback is generated at I401 output (pin 5) by means of C403 and D411 and a flyback generator internal to I401. After vertical flyback, the I401 output generates a negative going ramp across the field deflection coil which provides deflection until the next flyback pulse and so on. R413 is used to damp oscillation of the field deflection coil. Vertical deflection amplifier stability against self oscillation is maintained by R412, C404 and C402.

15

Vertical Protection
When operating normally, the vertical output stage generates a +5.5V pulse during vertical flyback blanking. This pulse is fed via Q407 to I501 beam current input. Should this pulse fail, the picture tube outputs are "blanked off" until after about 12 seconds, the micro controller records a failure. For diagnostic purposes, vertical protection during the 12 second interval may be disabled by pressing the '2' key on the remote control handunit when in service parameter 'OA'. This should always be re-enabled after repair (See adjustments section).

16

TUBE BASE PANEL
The picture tube amplifiers produce high voltage CRT electrode drives from the low voltage RGB outputs of the TDA884x (I501). They also produce black current information to maintain the grey-scale characteristics which is returned to the colour decoder (I501). Also included is circuitry for picture blanking during switch on. The picture tube aquadag, (P901), is used to provide beam current information for the colour decoder for the purposes of beam current limiting. The tubebase socket (P902) is fitted with internal spark gaps. D910 provides tube base protection when the spark gaps flash-over. The panel includes supplies to the tube electrodes and the video amplifiers. Focus and A1 supplies are connected directly from the flying leads of T401.

Video Drives
All video drive adjustments are done via the I˛C bus (See adjustments section) with the exception of the black level set point (140V) which is set by the A1 control on the line output transformer (T401). An additional feature for diagnostic purposes is the ability to disable the auto black level circuit by pressing '2' on the remote control hand set when in service parameter 02 (See adjustments section)

Tubebase Video Amplifier Circuit
Each video amplifier channel includes a bipolar cascode amplifier. A R, G or B signal from the colour decoder (I501) is fed to each video amplifier input. The low frequency gain of each video amplifier is approximately 51, this being determined by the ratio of the feedback resistors to the input resistors. The gain of each video amplifier channel above 2.2 MHz is increased by including a small capacitor across one of the two input resistors of each channel.

Video Amplifier Switch-On Blanking
The emitters of Q906, Q907 and Q908 are biased from the +200V video HT via R917, R905 and Q910. The +13V supply to bias the base connections of Q902, Q905 and Q908 is switched on under control from microcontroller I701 pin 35 (via R435, Q408 and R434 on the main panel) during power up or from standby after emitter bias of Q906, Q907 and Q908 is established. Thus picture blanking during power up or from standby is ensured.

Auto Grey Scale
During the field blanking period the colour decoder (I501) measures the total cathode circuit leakage currents at the video amplifier outputs via Q901, Q902 and Q903: - During field blanking, the colour decoder applies monitoring pulses to the video amplifier inputs and thence current outputs from Q901, Q902, Q903 are applied to the colour decoder pin 18 via R904 and R516. (During normal unblanked picture operation, the colour decoder ignores the information on its pin 18.) . The current outputs from Q901, Q902 and Q903 are used by I501 to adjust the black current and video gain of each video channel automatically. Thus black level picture beam current and black to white video drives are maintained. Diodes D903, D905 and D906 prevent horizontal smearing/ shadowing of the OSD from spreading across the screen.

17

TDA884X Video Processor
Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 27 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49I 50 51 52 53 54 55 56 Designation SNDIF AUDIOEXT NC NC PLLLF IFVO SCL SDA DECBG CHROMA CVBS/Y VP1 CVBSINT GND 1 AUDIOOUT SECPLL CVBSEXT BLKIN BO GO RO BCLIN RI GI BI RGBIN LUMIN LUMOUT BYO RYO BYI RYI REFO XTAL1 XTAL2 DET VP2 CVBS1O DECDIG HOUT FBISO PH2LF PH1LF GND2 EWD VDRB VDRA IFIN1 FIN2 EHTO VSC IREF DECAGC AGCOUT AUDEEM DECSDEM I/O I I Description Sound IF External Audio Not Connected Not Connected IF-PLL loop filter IF Video Serial Clock Serial data Bandgap de-coupling Chrominance External CVBS/Y Main supply voltage 1 (+8V) Internal CVBS Ground 1 Audio SECAM PLL de-coupling External CVBS Black-current Blue Green Red Beam current limiter input/V-guard input Red input for insertion Green input for insertion Blue input for insertion RGB insertion Luminance Luminance (B-Y) signal (R-Y) signal (B-Y) signal (R-Y) signal Sub-carrier reference 3.58MHz crystal connection 4.43/3.58MHz crystal connection Loop filter phase detector 2nd supply voltage 1 (+8V) CVBS-1 De-coupling digital supply Horizontal Flyback input/sandcastle output Phase-2 filter Phase-1 filter Ground 2 East-west drive Vertical drive B Vertical drive A IF input 1 IF input 2 EHT overvoltage protection Vertical sawtooth capacitor Reference current AGC de-coupling capacitor Tuner AGC Audio de-emphasis De-coupling sound demodulator

O I I/O I I I O I I O O O I I I I I I O O O I I O

O O I/O

O O O I I I I O

Table 2 ­ TDA884X Pin Designations

18

TUNER SCL H-DRIVE
43 39 14 44 12 37 9 42 41 40

SD AA
8

54

53

7

48

VIF AMPLIFIER TOP I˛C BUS TRANSCEIVE R SYNC SEP. + 1st LOOP VCO + CONTROL 2nd LOOP HOR. OUT

IF-IN POL

49

+ PLL DEMOD

+ CALIBRATION

AGC FOR IF + TUNER

50 46 47

EHT

5

AFC

VIDEO AMPLIFIER VERT. SYNC. SEPARATOR H/V DIVIDER

CONTROL DAC's

VERTICAL GEOMETRY

V. DRIVE

9.2

52 51

AFC MUTE CHROMA TRAP + BANDPASS REF SW LUMA DELAY PEAKING CORING HUE SW CVBS SWITCH PAL/NTSC SECAM DECODER
35 13 1 38 10 11 36 34 16 33

Fig 7
FILTER TUNING CVBS-Y/C SWITCH REF BASE-BAND DELAY TIME
CVBS OUT C V B S I N C C h V r B S/ Y

IDENT

WHITE P CONTINUOUS CATHODE CALIBRATION

BRI

CONTR RGB CONTROL BLUE STRETCH OUTPUT
21 20 19 22 18 R G B BEAM CURR BLACK CURR

VIDEO IDENT

VIDEO MUTE

TDA884X Video Processor

Block Diagram
FSC

19

AUDIO OUT

15 55

2

AUDIO IN

AVL +

SWITCH +

VOLUME

PRE-AMP. + MUTE

BLACK STRETCH RGB MATRIX RGB 1 INPUT SAT CD MATRIX SAT. CONTROL SKIN TINT

45

23 24 25 26

R1 G1 G1 BL1

VOL

SW

56

LIMITER

PLL DEMOD.

6

SOUND BANDPASS

SOUND TRAP

Remote Control
The remote control system used is the Philip's Enhanced RC5 protocol, with sub-address 00000.

Infra-red Transmitter
The hand unit is controlled by IC781, type PCA84C122AT/093, surface mounted on the keypad side of the PCB. When replacing the part, the /093 is significant as it determines the key codes transmitted. Two AA type batteries in series provide a 3V power supply. The IC remains in standby mode (oscillator not running) until a key on the matrix is pressed. The oscillator, governed by a 4MHz ceramic resonator XL781 is started. The IC decodes the key with suitable debounce and then transmits the relevant code, repeating as per the RC5 specification until the key is released. The RC5 pulse train output is modulated within the IC onto a 33.33kHz (f.osc/120) carrier with low (1:3) hark:space ratio, reducing power consumption and allowing higher LED current. The output on pin 21 of IC781 drives TR781 which provides high current pulses through infra-red transmitter diode D781. Reservoir capacitor CE781 reduces momentary battery voltage drop which may otherwise affect the IC.

Infra-red Receiver
The chassis uses an integrated receiver, IC702, which provides a fully demodulated output to the microcontroller through R703, pulled up by R702. Keypad N° 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 * ** Table 3 Symbol ! ." 1 2 3 4 5 6 7 8 9 0 Functions Standby N° 1 N° 2 N° 3 N° 4 N° 5 N° 6 N° 7 N° 8 N° 9 N° 0 TV *Text/*Mix Keypad N° 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Symbol Functions

# Programme Up $" Increase Volume %" Decrease Volume
*Fastext (RED) Menu/*Fastext (GREEN) Menu/*Fastext YELLOW) Menu/*Fastext (CYAN) Normalize/*Hold &" *Expand '" Status/*Fastext Index )" +"AV Select - *Time/*Subcode **Audio /" Select *Update 1" (" *Reveal

*"
,"

These functions are only present on chassis fitted with teletext These functions are only present on chassis fitted with stereo Keypad Idents and Functions

." Programme Down 0" Mute

20

Microprocessor Control System
Microcontroller
Micro-controller, I701, is either a SAA5288 (on non-teletext sets) or a SAA5290 (on teletext sets). Both devices have integrated on-screen display (OSD) generator; the SAA5290 also has an integrated teletext decoder. The micro-controller has a single 12MHz crystal X701. The television is controlled by serial (I˛C) bus communication, digital switching inputs and outputs, analogueto-digital inputs and pulse-width-modulation (PWM) outputs.

Reset
At power on, C709 is not charged so the voltage on pin 43 of the micro-controller rises with the 5V supply and resets the micro-controller. An internal resistor to ground at this pin causes C709 to charge up and the voltage on the reset pin to drop to 0V. In normal operation, transistor Q702 is switched on and the reset pin is low, but if the 10V supply voltage drops below about 8V the transistor will switch off and R721 will pull the reset pin high and reset the device.

User Control
User input is via infra-red remote control (Philips' RC5 protocol), internally decoded from the receiver I703, or from three (non-matrixed) local control keys on active low inputs, I701 pins 18, 19 and 20. The LED flashes each time a key is detected or remote command received.

Tuning
The tuning control voltage to the tuner is controlled via the PWM at pin 1 of I701 and integrating circuit around Q001. Minimum voltage is at maximum mark-space ratio (bottom of each band). Band-switching is controlled by active low outputs on pins 14, 15 and 16 (high, mid, low) and transistors Q002 to Q004. The controller makes AFC corrections by reading on-tune information from I501 via the I˛C bus. As the tuner is controlled by voltage synthesis, there is no direct correlation between the controller output and the tuned frequency.

Non-volatile memory
The non-volatile memory, I702, holds configuration information, user settings, parameters as applicable for I˛C controlled ICs and the programme tuning records. It is itself accessed by I˛C. When a new memory IC is fitted, the microcontroller will automatically load default information, which takes a few seconds during power-up. Regular re-loading of the data, or corruption of settings may indicate I702 is faulty.

AV switching
Inputs from pins 8 and 16 of SCART 1 are sampled by analogue to digital conversion on pins 9 and 10 of I701 respectively. The input levels are adjusted such that the controller will automatically switch to AV1 when pin 8 is above 6V and RGB when pin 16 is above 1V. The time constant on pin 16 ensures the controller will not detect real-time RGB insertion using pin 16.

21

OSD / Teletext
Line and field timings are obtained from V.sync on pin 37 and H.sync input on pin 36. Teletext (on teletext sets only) is obtained from the CVBS input on pin 23. The RGB outputs on pins 34, 33 and 32 respectively are inserted into the TV output when gated by the OSD EN OUT signal on pin 35. OSD / teletext contrast is controlled by the peak reference level on pin 31, generated from the microcontroller PWM output on pin 2 via Q305.

Error codes
Under the following fault conditions the television will switch to standby and flash the LED. Fault Condition Multiple TDA884X I˛C errors Over voltage / X-ray protection (OVP) Line start-up sequence failed Black current (BC) loop unstable Vertical scan failure Continuous TDA884X power-on reset No. of Flashes 1 2 3 4 5 6

Multiple error codes may appear, eg. two quick flashes, pause, four quick flashes etc. for OVP + BC loop errors.

Adjustments
In order to make service adjustments including setting the height, width, various configuration options, etc., the TV should have a suitable signal tuned in; ideally, a geometry test card. A teletext signal is recommended for setting OSD contrast on a teletext chassis. To enter service mode, place a shorting link across terminals 2 and 3 of P701. In service mode, two 2-digit hexadecimal numbers are displayed to the left of the screen; the lefthand one is the service parameter number, the righthand one is the value for that parameter. Some parameters are identified by a two-letter code instead of a number, see below. For example: 0A 1F shows parameter ten (0A hex) at thirty-one (1F hex). In this mode of operation some of the remote control keys have different functions; The up and down and local select keys are used to select a parameter. The remote and local left and right keys are used to change the value of the current parameter. The TV button is used to store any changes. The teletext select and digit '0' keys are used for programme up or down. The Normalize key selects factory picture settings immediately over-writing user settings. The digit keys '1', '2',----'8' toggle the state of the individual bits '7', '6',----'0' of the value of the current parameter, for example, pressing digit key '4' would change value 1F hex to 0F hex. TO STORE THE CHANGES, PRESS THE TV KEY ON THE HAND UNIT BEFORE REMOVING THE SERVICE MODE LINK. THE MESSAGE 'STORED' WILL BE DISPLAYED TO CONFIRM THE OPERATION. Under certain circumstances, for example abnormal operation due to suspected corruption of the service parameters, it may be necessary to perform a complete reset of the non-volatile memory (I702). To effect this, press and hold the X (teletext update) key for about 3 seconds or until the set switches to standby . Following this it will be necessary to perform a 'set-up' of the television.

22

Service Parameters
The following values assume you are watching a tuned in picture, on RF. (On other sources, or with no signal, some values may differ.) Service parameters 00 to 1A apply to the control registers of I501 as shown in the following table. No. 00 01 02 Value 14" 02 D0 1F Function 20" 02 D0 1F 21" 02 D0 1F Action Do not adjust Do not adjust Use picture menu control instead Adjust to centre picture horizontally Not used on this chassis Adjust for vertical linearity Adjust for correct picture height Adjust for best vertical S-correction Adjust to centre picture vertically See adjustments section Use picture menu control instead Use picture menu control instead Use picture menu control instead Use picture menu control instead See adjustments section Set to 50 hex. Not used on this chassis Not used on this chassis Do not adjust Do not adjust Do not adjust

System control System control Hue (SCART NTSC 4.43 playback only) 03 20 1D 27 Horizontal shift 04-07 00 00 00 E-W control 08 20 1F 1E Vertical slope (linearity) 09 10 0B 1A Height 0A 44 4A 4A S-correction 0B 2B 1B 1B Vertical shift 0C 29 38 3D White point - Red 0D 29 38 3D White point - Green 0E 29 38 3D White point - Blue 0F 1C 1C 1C Peaking (sharpness) 10 5C 5C 5C Brightness 11 9C 9C 9C Saturation 12 1C 1C 1C Contrast 13 13 13 13 AGC take-over point 14 0A 0A 0A Volume 15 50 50 50 IF PLL adjustment 16 19 19 19 Vertical zoom 17 20 20 20 Vertical scroll 18 81 81 81 Control 2 19 08 08 08 Control 3 1A 00 00 00 Control 4 Table 4 Service Parameter Functions

Parameters above 1A are designated by two-letter codes (except text contrast on a teletext set). These control configuration. Text Mode Ex AV Text (OSD) contrast Export (VHF/UHF) setting AV socket configuration Set as preferred, see notes below 00 for UHF-only, 01 if multi-band tuner 00 single SCART, 01 single SCART plus phono inputs

It is advisable to make a note of the existing values prior to commencing servicing. (See adjustments section).

23

Microprocessor Pin-outs
Pin
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 NOTE

Designation
P2.0/TPWM P2.1/PWM0 P2.2/PWM1 P2.3/PWM2 P2.4/PWM3 P2.5/PWM4 P2.6/PWM5 P2.7 P3.0/ADC0 P3.1/ADC1 P3.2/ADC2 P3.3 Vssd P0.0 P0.1 P0.2 P0.3 P0.4 P0.5 P0.6 P0.7 Vssa CVBS0 CVBS1 Black Iref Frame Test COR P3.4 RGBref OSD B OSD G OSD R OSD EN H sync V sync Vdda Vddt Osc gnd Osc in Osc out Reset Vddm P1.0/Int1 P1.1/T0 P1.2/Int0 P1.3/T1 P1.6/SCL P1.7/SDA P1.4 P1.5 !

I/O
O O O O O O O O

Purpose
Tuning PWM Text contrast PWM AV audio control: high = AV2, low = RGB/AV1 !FM/AM source select (low = AM) !SCART/internal sound select (low = internal sound) !L' control select (active high) Pseudo line drive Force RGB high = RGB mode AV1 SCART pin 8 level detection (ADC) AV1 SCART pin 16 level detection (ADC) AGC level sampling (ADC) ­ Digital ground High band tuner select (active low) Mid band tuner select (active low) Low band tuner select (active low) Audio mute control (active low Select key Down key Up key ­ Analogue ground Composite video ­ Video black level storage Reference current ­ Ground ­ TDA884X Line drive gating: high in standby & start-up, low in operation RGB reference Blue OSD Green OSD Red OSD OSD enable Horizontal sync Vertical sync +5V display power supply +5V display power supply Crystal oscillator ground 12MHz crystal oscillator 12MHz crystal oscillator Reset (active high) +5V microcontroller power supply Remote control Standby/IR LED: low = LED bright, high = LED dim Line drive from TDA884x Standby control (active low) I˛C clock I˛C data Service mode (active low) Halt microcontroller control (active low) Only used on French chassis

I I I O I I I

I I I

I O O O O I I

I O I I O I O

I I

Table 5

Pin Descriptions

24

SAA5290 (Teletext) & SAA5288 (Non-teletext) Microcontrollers
Note: The SAA5288 microcontroller used on non-teletext models does not perform the functions in the shaded area.

Black

IRef Teletext Acquisition Page RAM R,G,B, VDS, COR VSync HSync Frame

CVBS0, CVBS1

Data Slicer

Display

Acquisition Timing

Display Timing

16k x 8 ROM Reset 8051 CPU
data addr int

256 x 8 RAM

Text Interface

I˛C

Osc Timer/ Ctrs ADC Port 0 Port 3 PWM Port 2

XtalIn XtalOut OscGnd

Port 1

P1.0 ­ 1.7 P0.0 ­ 0.7
Fig 8

P3.0 ­ 3.4 P2.0 ­ 2.7
Block Diagram

25

USER GUIDE
Operating Instructions
Using the Menus
Green Key Yellow Key Blue Key Red Key
Selects the PICTURE controls menu.

Selects the MANUAL/TUNING menu. Selects the FEATURES menu. Used only within the other menus above.

The green, yellow and blue keys select the Menus as listed above. See pages 3 and 4 for full details of their functions. In Teletext mode they enable quick access to topical subjects related to the magazine you have selected. Just press the key with the same colour as the topic at the foot of the page.

Up/Down Keys

(P+/P-) Move the cursor (coloured bar) when using Menus.

When viewing television these keys will select next/previous TV station. When using Teletext these keys will select next/previous pages.

Left/Right Keys

(vol ­ or !­) / (vol + or !+) Move the cursor (coloured bar), or makes adjustments when using Menus.

In TV and Teletext mode they will adjust the volume down and up.

Remote Control Hand Units

FX700 RCHU

FX701 RCHU

26

84

85

86

87

88

89

90

91

92

93

94

95

96

Section 15 COMPONENTS LIST
14" Models Chassis type 20" Models Chassis type 21" Models Chassis type C1422R F1R C1422T F1Y CP1422R F1GR CP1422T F1GY CP2022T F2GY CP2122T F4GY CP1422T-481 F1HY CP1422T-491 F1HY CP2022T-491 F2HY CP2122T-491 F4HY CL1422R F1FR CS1422R F1KR CS2022R F2KR CS2122R F4KR

C2122T F4Y

CP2122R F4GR

CP2122T-481 F4HY

CL2122R F4FR

Critical Safety Components A number of electrical components in this television contribute to operating safety, and the protection afforded by them cannot necessarily be maintained by using replacement components rated for higher voltage, wattage etc. They are identified by ! in the parts list and on the circuit diagram to indicate that only manufacturer' s approved replacements are to be used.
15.1 CAPACITORS The following components are common to all chassis Cct Ref. Val C001 22µ C002 100n C004 100µ C005 100n C006 22n C007 100n C008 100n C011 100n C301 100µ C302 100n C305 470n C308 470n C401 10µ C402 4n7 C403 100µ C404 100n C405 1µ C406 330n C407 22µ C408 470µ C409 1000µ C412 1µ C413 10000p C414 100n C415 100n C416 22µ C417 33n C418 470p C420 100n C421 22µ C422 100n C423 100n C436 100n C501 100n C502 22µ C503 68p C504 15p C505 33p C506 47n C507 22µ C508 47µ C509 47n C510 2µ2 C511 22n C512 47n C513 100n C515 47n Tol.% 20 20 20 20 20 5 5 5 20 20 5 5 20 20 20 5 5 5 20 20 20 20 10 5 5 20 20 5 20 20 20 20 20 20 20 5 5 5 20 20 20 20 20 20 20 20 20 Volts 25 50 25 50 50 63 63 63 25 50 63 63 50 50 35 100 63 63 250 25 25 63 500 100 100 25 50 50 50 16 50 50 50 50 25 50 50 50 50 25 25 50 50 50 50 50 50 Xpos(track) Xpos(comp) Ypos 189.00 25.00 12.50 195.00 19.00 12.00 201.00 13.00 64.50 204.50 9.50 42.85 173.50 40.50 15.60 177.10 36.90 11.90 193.75 20.25 190.50 197.60 16.40 217.00 169.75 44.25 145.50 167.25 46.75 143.50 189.50 24.50 192.50 192.70 21.30 214.00 71.00 143.00 45.00 93.50 120.50 66.50 82.00 132.00 69.50 80.00 134.00 43.00 95.50 118.50 48.75 61.20 152.80 101.80 72.50 141.50 15.00 92.75 121.25 22.50 91.50 122.50 38.75 53.75 160.25 92.50 50.50 163.50 72.45 93.50 120.50 45.00 61.50 152.50 12.00 97.10 116.90 148.50 80.00 134.00 88.00 85.50 128.50 90.50 94.35 119.65 145.25 95.50 118.50 130.75 94.50 119.50 139.00 83.15 130.85 9.50 97.10 116.90 14.30 161.50 52.50 75.50 145.50 68.50 54.00 135.80 78.20 120.30 161.50 52.50 65.50 162.55 51.45 19.20 152.50 61.50 84.50 185.10 28.90 43.50 151.50 62.50 82.00 161.50 52.50 81.50 154.50 59.50 76.50 151.00 63.00 78.50 145.50 68.50 80.00 169.50 44.50 90.00 140.25 73.75 87.15 Type Elect 85° C Y5V S.M.0805 Elect 85° C Y5V S.M.0805 Y5V S.M.0805 Metal polyester Metal polyester Metal polyester Elect 85° C Y5V S.M.0805 Metal polyester Metal polyester Elect 85° C X7R S.M.0805 Elect Metal polyester Metal polyester Metal polyester CEO4W Elect Elect 85° C Elect 85° C CF93M Metal DC CK45 Metal polyester Metal polyester Elect 85° C Y5V S.M.0805 Ceramic Y5V S.M.0805 CEO4W Elect Y5V S.M.0805 Y5V S.M.0805 Y5V S.M.0805 Y5V S.M.0805 Elect 85° C COH S.M.0805 COH S.M.0805 COH S.M.0805 X7R S.M.0805 Elect 85° C Elect 85° C X7R S.M.0805 Elect 85° C X7R S.M.0805 X7R S.M.0805 Y5V S.M.0805 X7R S.M.0805 Part No. T5213422091 T5280810491 T5213410191 T5280810491 T5230822391 T5275110491 T5275110491 T5275110491 T5213410191 T5280810491 T5275147491 T5275147491 T5213610091 T5230847291 T5213510191 T5271110491 T5275110591 T5275133491 T5214422012 T5213447101 T5213410212 T5275110591 T5232310301 T5271110491 T5271110491 T5213422091 T5280833391 T5247047191 T5280810491 T5213322091 T5280810491 T5280810491 T5280810491 T5280810491 T5213422091 T5240868091 T5240815091 T5240833091 T5230847391 T5213422091 T5213447091 T5230847391 T5213622991 T5230822391 T5230847391 T5280810491 T5230847391

97

Cct Ref. Val C516 270p C517 270p C518 47n C519 270p C520 47n C521 270p C522 47n C523 270p C524 10p C525 10p C528 100n C529 4n7 C530 47n C531 100µ C532 2n2 C533 4n7 C534 1µ C535 1n C536 1n C537 1n C538 100n C539 2µ2 C541 10µ C542 100p C543 22n C601 1000µ C602 100n C603 2n2 C604 1n C605 56p C606 330p C607 100n C608 470n C609 22n C610 47n C611 330p C612 470n C613 22n C614 10µ C615 3n9 C616 330p C618 100µ C619 1n C701 100n C702 100n C703 22µ C704 22p C705 22p C706 100n C707 47n C708 100n C709 0µ47 C710 270p C711 100µ C712 100µ C713 100n C714 10n C715 1n C717 100n C718 100n C719 100n C720 100n C749 10000p ! C801 220n C802 1n C803 1n 3n3 ! C804 C805 100µ

Tol.% 5 5 20 5 20 5 20 5 5 5 20 20 20 20 10 20 20 10 10 10 5 20 20 5 20 20 20 10 10 5 5 20 5 20 20 5 5 20 20 10 5 20 10 20 20 20 5 5 20 20 5 20 5 20 20 20 20 10 20 20 20 20 10 20 20 20 20 20

Volts 50 50 50 50 50 50 50 50 50 50 50 50 50 10 50 50 50 50 50 50 63 50 50 50 50 16 50 50 50 50 50 50 63 50 50 50 63 50 50 50 50 10 50 50 50 25 50 50 50 50 63 50 50 25 25 50 50 50 50 50 50 50 500 250 250 250 400 400

Xpos(track) Xpos(comp) Ypos 168.00 46.00 16.50 150.50 63.50 5.25 153.00 61.00 101.20 144.50 69.50 5.25 148.00 66.00 102.75 136.50 77.50 5.25 153.00 61.00 104.50 154.00 60.00 5.25 180.50 33.50 109.50 177.50 36.50 109.50 169.00 45.00 109.50 167.50 46.50 98.00 167.50 46.50 95.50 191.50 22.50 97.00 169.50 44.50 85.25 184.00 30.00 85.50 187.50 26.50 87.50 167.50 46.50 80.00 167.50 46.50 77.50 167.55 46.45 71.20 178.50 35.50 71.00 170.25 43.75 57.50 178.00 36.00 81.00 141.40 72.60 90.25 143.50 70.50 91.85 179.10 34.90 133.60 177.65 36.35 136.50 194.00 20.00 133.00 164.00 50.00 49.00 148.50 65.50 50.00 161.50 52.50 56.00 126.00 88.00 41.50 122.00 92.00 35.00 127.50 86.50 20.50 177.75 36.25 120.50 119.50 94.50 8.50 125.50 88.50 65.75 110.50 103.50 12.00 175.50 38.50 57.50 182.00 32.00 62.00 132.00 82.00 24.10 177.70 36.30 140.00 120.50 93.50 58.50 132.50 81.50 200.25 167.60 46.40 184.45 187.50 26.50 231.00 167.60 46.40 179.95 167.60 46.40 177.70 167.60 46.40 174.00 150.00 64.00 173.00 76.00 138.00 80.50 123.50 90.50 217.00 139.00 75.00 5.25 153.50 60.50 181.00 157.40 56.60 204.00 184.50 29.50 180.50 135.50 78.50 200.25 167.60 46.40 182.20 174.10 39.90 168.20 174.10 39.90 165.95 174.10 39.90 163.70 189.50 24.50 189.50 81.50 132.50 76.00 61.50 152.50 163.50 34.00 180.00 169.00 13.00 201.00 168.00 84.00 130.00 164.50 37.00 177.00 143.00

Type COH S.M.0805 COH S.M.0805 X7R S.M.0805 COH S.M.0805 X7R S.M.0805 COH S.M.0805 X7R S.M.0805 COH S.M.0805 COH S.M.0805 COH S.M.0805 Y5V S.M.0805 X7R S.M.0805 X7R S.M.0805 Elect 85° C X7R S.M.0805 X7R S.M.0805 CE04W Elect X7R S.M.0805 X7R S.M.0805 X7R S.M.0805 Metal polyester Elect 85° C Elect 85° C COH S.M.0805 X7R S.M.0805 CE04E Elect Y5V S.M.0805 X7R S.M.0805 X7R S.M.0805 COH S.M.0805 COH S.M.0805 Y5V S.M.0805 Metal polyester X7R S.M.0805 X7R S.M.0805 COH S.M.0805 Metal polyester X7R S.M.0805 Elect 85° C Ceramic plate COH S.M.0805 Elect 85° C X7R S.M.0805 Y5V S.M.0805 Y5V S.M.0805 Elect 85° C COH S.M.0805 COH S.M.0805 Y5V S.M.0805 X7R S.M.0805 Metal polyester Elect 85° C COH S.M.0805 Elect 85° C Elect 85° C Y5V S.M.0805 X7R S.M.0805 X7R S.M.0805 Y5V S.M.0805 Y5V S.M.0805 Y5V S.M.0805 Y5V S.M.0805 DC CK45 AC Mains X2 AC Ceramic AC Ceramic AC R12.5 Cls Y Elect 105° C

Part No. T5240827191 T5240827191 T5230847391 T5240827191 T5230847391 T5240827191 T5230847391 T5240827191 T5240810091 T5240810091 T5280810491 T5230847291 T5230847391 T5213210191 T5230822291 T5230847291 T5213601091 T5230810291 T5230810291 T5230810291 T5275110491 T5213622991 T5213610091 T5240810191 T5230822391 T5213310212 T5280810491 T5230822291 T5230810291 T5240856091 T5240833191 T5280810491 T5275147491 T5230822391 T5230847391 T5240833191 T5275147491 T5230822391 T5213610091 T5231339291 T5240833191 T5213210191 T5230810291 T5280810491 T5280810491 T5213422091 T5240822091 T5240822091 T5280810491 T5230847391 T5275110491 T5213647891 T5240827191 T5213410191 T5213410191 T5280810491 T5230810391 T5230810291 T5280810491 T5280810491 T5280810491 T5280810491 T5232310301 T5270106201 T5230106991 T5230106991 T5230133201 T5210313800

98

Cct Ref. Val C806 1000p C807 4n7 C809 100µ C810 4n7 C811 10000p C812 1000µ C813 330n C814 100n C815 100n C817 470p C901 33n C902 1000µ C903 68p C904 1000p C905 1000p C906 60p C907 100n C908 100n C909 60p C910 22p C912 33p C913 22p C914 100n C915 100n C916 100n CA501 270p CA601 22n CA602 1000p

Tol.% 10 20 20 10 20 5 5 20 10 10 20 5 10 10 5 20 20 5 5 5 5 20 20 20 5 20 10

Volts 500 50 250 500 500 16 63 63 50 500 250 16 50 500 2kV 50 50 50 50 50 50 50 50 50 50 50 50 50

Xpos(track) Xpos(comp) Ypos 51.75 162.25 146.25 8.00 206.00 117.65 50.50 163.50 120.50 60.50 153.50 108.00 51.50 162.50 103.00 91.00 123.00 114.50 97.00 117.00 115.00 104.75 109.25 126.00 49.50 164.50 109.15 48.50 13.00 23.25 93.50 44.50 23.25 24.50 30.35 25.50 3.35 3.35 3.35 8.00 8.85 29.10 165.50 201.00 190.75 120.50 169.50 109.75 189.50 183.65 188.50 210.65 210.65 210.65 206.00 205.15 184.90 198.50 227.50 205.35 201.50 237.50 220.35 196.65 215.00 235.25 203.50 231.00 218.00 209.65 225.00 230.00

Type Part No. DC Ceramic T5232310291 X7R S.M.0805 T5230847291 Elect 105° Low ESR T5216007100 C Ceramic T5232347291 DC CK45 T5232310301 CE04W Elect T5213310212 Metal polyester T5275133491 Metal polyester T5275110491 Y5V S.M.0805 T5280810491 Ceramic disc T5232347191 Metal polyester T5272233391 Elect 85° C T5213310201 COH S.M.0805 T5240868091 DC Ceramic T5232310291 T5234210201 COH S.M.0805 T5240868091 Y5V S.M.0805 T5280810491 Y5V S.M.0805 T5280810491 COH S.M.0805 T5240868091 COH S.M.0805 T5240822091 COH S.M.0805 T5240833091 COH S.M.0805 T5240822091 Y5V S.M.0805 T5280810491 Y5V S.M.0805 T5280810491 Y5V S.M.0805 T5280810491 COH S.M.0805 T5240827191 X7R S.M.0805 T5230822391 DC Ceramic T5231310291

15.1.1

Capacitor Differences Table (14" Models)
C1422T F1Y T5213410191 T5280810491 T5280810491 T5280810491 T5270208501 T52703