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D99 CHASSIS
OPERATION MANUAL TROUBLESHOOTING MANUAL
TABLE OF CONTENTS
CIRCUIT DESCRIPTION D Board (Power Supply Section) ............. 2 D Board (Deflection Section) ................... 9 A Board .................................................. 20 GENERAL TROUBLESHOOTING .............. 26 PARTS LEVEL BOARD REPAIR ................ 37
TRINITRON® COLOR COMPUTER DISPLAY
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CIRCUIT DESCRIPTION D BOARD POWER SUPPLY SECTION Power Supply Electrical Circuit
The power supply is located on the D Board. It has three modes of operation that are controlled by a microprocessor. The topology is a discontinuous mode flyback converter with photocoupler feedback for regulating the secondary voltages. Circuit operation and troubleshooting are explained in the following sections:
Operation Modes AC Input Degauss Circuit Primary Circuitry Operation Modes
Secondary Circuitry Protection Circuits Troubleshooting
The power supply has four modes of operation, `off', `active off', `suspend/standby' and `active on'. These modes are related to power savings and are indicated by the front panel LED. Additional indications are failure diagnostics and aging mode. The table below lists operation mode, condition and LED status.
Mode Off Active Off Suspend/Standby Active On Failure 1 Failure 2 Failure 3 Aging/Self Test Syncs N/A No H and V No H or V H and V Present NA NA NA No H and V Condition Power Switch Off Low Power, Heater Off Low Power, Heater On Phase Locked, Normal Operation HV or +B Failure H Stop, V Stop, Thermal Failure ABL Failure Aging Raster or Test Pattern LED Off Amber Amber 0.5s<- ->Green 0.5s Green Amber 0.5s<- ->Off 0.5s Amber 1.5s<- ->Off 0.5s Amber 0.5s<- ->Off 1.5s Green 0.5s<- ->Off 0.5s
Except for power switch off, all modes of operation are controlled by the microprocessor located on the D Board. The failure modes are detected by the microprocessor and the power supply is forced into active off mode. These functions are discussed later (Deflection). With the AC cord attached to the monitor and connected to an AC source, the monitor will be off until the power switch is turned on. When the power switch is turned on, the power supply starts and is in active off mode. The next step is active on mode. The power saving modes are activated by the microprocessor based upon the presence of either H or V sync. If no sync signals are present, the power supply is set to active off mode. If only horizontal sync is present the power supply moves to suspend mode. If only vertical sync is present the power supply enters standby mode. Power supply operation control signals are "Remote On/Off" and "Heater On/Off". Remote On/Off is digital low for active off and suspend/standby modes. Heater On/Off is digital low for active off mode. To enter active on mode, the microprocessor must set remote on/off to digital high. Heater on/off is also made digital high and the heater is turned on.
Output B+ 80V +15V -15V +12V 5V H eater H . C entering ST B Y 5V
Off 0V 0V 0V 0V 0V 0V 0V 0V 0V
Active Off 13V 10V 1V -1V 0V 0V 0V +5V
Suspend/Standby 180V 77V 14V -14V 0V 0V 4.6V +7V +5V
Active On 180V 79V +15V -15V +12V +5V 6.3V +10V +5V
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AC Input and Degauss
1. AC Input Section
The AC input section provides EMI filtering, input protection, surge limiting and CRT degauss operation.
EMI Filter
The EMI filter comprises CN600 (inlet with filter), X-capacitors C604 and C605, Y-capacitors C606, C638, C660 and C643 and the line filter transformer, LF602. Input protection is provided by F601and VA601; surge current limiting by thermistor TH600 and resistor R600. Degauss is explained in the next section.
Degauss Circuit
The degauss circuit is used to demagnetize the CRT. After power on, the microprocessor located on the D Board sets the degauss signal to digital high and Q601 turns on relay RY601. This allows AC current into the degaussing coil through posistor TH601. The current heats up the posistor and its affective resistance increases, this dampens the current in the degauss coil to nearly zero. Duration time is approximately 5-6 seconds and the microprocessor then shuts off RY601, which disconnects the degauss coil from the AC line. This operation should sufficiently demagnetize the CRT.
2. Primary Circuitry Section
IC601 The heart of the primary section is the TEA1504/N2 power supply controller, IC601. The following describes the functions of each pin. Pin 1 Vin: This is a MOSFET drain connection internal to IC601, which is connected directly to the DC mains voltage rail. The startup current source derives power from the DC mains via the Vin pin. It supplies current to charge the Vaux (IC supply) capacitors C616 and C617 and also provides current to the IC601 control circuitry. Pin 2 HVS: High voltage safety spacer pin is a no connection. Pin 3 NC: Connected to primary side DC mains return.
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Pin 4 Driver: Outputs the pulse width modulated gate drive for switching transistor Q602. Maximum duty cycle is set internally at 80%. Pin 5 Isense: Provides cycle by cycle over current protection by turning off pin 4 driver output when Q602 current exceeds the current limit corresponding to 500mV at pin 5. This pin typically provides 425nS of leading edge blanking time. The threshold voltage for switch over to low frequency (low power) operation is sensed by pin 5. When the voltage sensed at pin 5 is below 165mV, IC601 transitions from operating at high frequency (56.5KHz) to low frequency (23.5KHz). Pin 6 Vaux: IC601 supply pin. An internal current source from IC601 charges the Vaux capacitors C616 and C617 for startup. Once the Vaux capacitors are charged to the startup voltage level (11V), then IC601 starts switching pin 4 driver output. The Vaux is also supplied by an auxiliary winding from T601 on the primary side once the secondary output voltages attain their nominal operating voltage values. Pin 6 also provides under voltage lockout detection (8V) and over voltage protection (14.7V). Pin 7 DS: Provides the power supply for the driver output (pin 4). Pin 8 Iref: Controls IC601 internal bias currents, which determines the pulse width modulated switching frequencies. High frequency is 56.5KHz during active on mode. Low frequency is 23.5KHz during suspend/standby mode. Pin 9 Vctrl: Feedback voltage for duty cycle control. Pin 10 NC: No connection. Pin 11 Gnd: Connected to primary side DC mains return. Pin 12 NC: No connection. Pin 13 Dem: Guarantees discontinuous conduction mode operation for the power supply. Verifies that T601 is demagnetized by not activating the next gate drive pulse until the primary side auxiliary winding of T601 is lower than the threshold level of 65mV as detected at pin 13. Pin 14 OOB: On/Off/Burst mode input signal. A voltage greater than 2.5V enables IC601.
Operation
The power supply is a discontinuous-mode flyback converter with photocoupler feedback for regulating the secondary voltages. The PWM controls the pulse width of the gate drive. When AC is applied to the power supply and IC601 pin 14 is greater than 2.5V, start up current is supplied though IC601 pin 1 to IC601 pin 6. Startup voltage is approximately 11V. After start up, the voltage to pin 6 and pin 7 of IC601 is supplied through D620 connected to T601 pin 2. The first mode of operation is active off mode. The output drive pulse frequency will be in burst mode operation. When the power supply enters active on mode, the switching frequency will be 56.5KHz. The Vaux level will be approximately 12.5 volts. OVP threshold is 14.7 volts and UVLO is 8.0 volts. Therefore, if the Vaux voltage is not correct, the power supply will not operate properly. Feedback from the secondary side comes through IC603 and IC604, which is connected to IC601 pin 9. (See diagram on page 5.)
3. Secondary Circuitry Section
The secondary section consists of the following circuits. Rectifier diodes and filters for all output voltages, horizontal centering, +5/12 volt regulators, +5 standby regulator, heater voltage regulator, voltage feedback circuit, active off mode feedback, and protection circuits. This section will describe each circuit and its function.
Secondary Rectifiers
The secondary rectifiers supply the following voltages, 180V (B+) deflection and video, 80V video, ±15V deflection and regulators, 6.3 volt heater regulator, +5V standby regulator, horizontal centering voltages.
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Horizontal Centering
This circuit supplies IC503, which is used to adjust horizontal raster position on the CRT. The horizontal centering circuit consists of fusible resistors R638 and R639, diodes D615 and D616 and filter capacitors C630 and C631. In respect to the secondary ground, the horizontal centering ground is floating and connected to H DY line. The voltages in reference to this floating ground are ±10 volts. Care should be taken to not short the floating ground to the secondary ground.
+5/12 Volt Regulator
IC605 is the 12 volt regulator and IC608 is the 5 volt regulator. The output voltages are supplied to the microprocessor, deflection and video circuits. The +15 volt line provides the input voltage for +12V regulator; the +12V line provides the input voltage for +5V regulator. During active off or suspend/standby mode, the 12 volt regulator is disabled via remote on/ off and subsequently the 5V regulator is disabled.
+5V Standby Circuit
IC607 is the standby 5V regulator. In the active on mode and the suspend/standby mode, the input to the regulator is supplied from T601 winding 14-13. During the active off mode, the regulator input is supplied from T601 winding 10-13 via D612 and D613. Typical input voltages to the regulator are active on mode: 9.5V; suspend/standby mode: 7.4V; active off mode: 11.5V.
Heater Voltage Regulator
Heater filament voltage is supplied by T601 winding 14-13 and is regulated by IC602. IC602 output is turned on and off by the heater on/off control line at pin 1, CTL. The output is off during active off mode.
Feedback Circuit
The feed back circuit is divided into two sections. One is for active on and suspend/standby modes; the other for active off mode. The following two sections explains the theory and operation.
Active On and Suspend/Standby Mode Feedback
Shunt regulator IC604 regulates the B+ line to 179.2V by sinking current through the opto coupler 1C603 to ground. The
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Feedback Circuits
reference voltage at IC604 pin 1 determines the sink current into pin 3. The reference voltage is set to 2.50 volts by resistor divider R608, R650, R648, and R609. Since the B+ is connected to the resistor divider, any change in B+ voltage is detected at the reference terminal. The shunt regulator will either increase or decrease the current into pin 3 in order to decrease or increase the B+ voltage respectively and try to maintain the reference voltage to 2.50 volts. IC603 biases it's phototransistor accordingly and drives IC601 pin 9 (Vctrl) which changes the duty cycle at IC601 pin 4 (driver) to regulate the B+ voltage at 179.2V.
Active Off Mode Feedback
Heater control line is low (heater off) during active off mode and respectively Q603 is off. Voltage pulses from T601 pin 10 flow through C620, R636, and R660 triggering the gate of thyristor D613. D613 turns on effectively shorting the B+ rail to the standby 5V regulator input; current flows from T601 pin 10 through D612 and D613 to the standby 5V regulator input. When the standby 5V regulator input is increased to approximately 12.7V it forward biases zener diode D605 turning on Q604 and sinks current through IC603 to ground. The standby 5V input supplies this current to IC603 pin 1. IC603 biases it's phototransistor and drives current through D609 into IC601 pin 14 (OOB) triggering burst mode operation. IC601 pin 4 (driver) is pulled low turning off switching transistor Q602. T601 pin 2 (auxiliary winding) feedback pulses are discontinued and IC601 pin 6 (Vaux) decreases to 8V. IC601 internal current source then charges pin 6 (Vaux) to the startup voltage level (11V) which starts switching pin 4 driver output. The feedback cycle is then repeated. The burst repetition rate is approximately every 110mS and when IC601 pin 4 is switching its frequency is 23.5KHz.
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Protection Circuits
4. Protection Circuits
The following are protection circuits: OCP, OVP, UVLO and secondary short circuits. OCP is pulse by pulse and is performed on the primary side. OVP detects excessive output voltages. UVLO detects output under voltages. The following will explain the operation of these functions.
OCP
OCP is activated if there is too much current passing through the power MOSFET, Q602. This condition will occur if either the B+ line or 80 volt line is shorted. R614 and R654 are the current sense resistors. Current through these resistors will produce a positive voltage reference to ground. R623, R624 and C650 provide a voltage divider and filter to IC601 pin 5 (Isense). If the voltage level exceeds 0.5 volts, the IC does pulse by pulse current limit and the output voltages are reduced. This condition can be audible and characterized by a `chirping' sound.
OVP and UVLO
The OVP and UVLO functions are detected by IC601 pin 6 (Vaux). Vaux is mornally 12.5V. In the event the regulation control loop were to fail, the output voltages would either increase or decrease; then Vaux would increase or decrease respectively via T601 transformer coupling. IC601 pin 6 will detect an OVP at 14.7V and UVLO at 8V turning off the driver output and initiating a low dissipation safe-restart mode.
Secondary Short Circuits
Safe operation during secondary short circuits is provided by the demag function of IC601 pin 13. Demag protection decreases the switching frequency to a very low level, thereby reducing the input power level and providing safe operation. Demag also provides a soft start function during startup gradually increasing the switching frequency until fixed frequency operation is attained.
5. Troubleshooting
Warning
Before attempting to fix the power supply, safety should be considered first. Never connect test probes to the primary side circuits, unless proper isolation has been installed. If isolation for the AC mains is not present, serious harm can occur. Never assume you are safe.
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No Power
In the event that the monitor does not turn on, first verify input power is applied to CN600 and the front panel power switch is turned on; then check F601 and R605. If these parts are blown, the primary side circuitry should be checked. If the fuses are not blown, then check the secondary side circuitry, especially the protection circuits. If these circuits are causing a no power symptom, the problem can be more readily found.
AC Input and Degauss Circuit Trouble Shooting
For no power or nonoperating power supply, the AC input circuitry should be checked. Open or short circuit elements will cause non-operation. F601, CN600, and R605 on the D Board should be checked first. Check the front panel power switch for continuity. If all elements are correct, check whether F601 breaks when power is applied and the power switch is closed. If the fuse does blow, there may be problems with the primary circuitry or a component short. The degauss will malfunction if CN601 is not connected. One problem could be loss of degauss signal from the microprocessor. This can be verified by using the manual degauss command found in the OSD menu. If the signal does not appear at Q601 base, then it is possible that the microprocessor does not function correctly or standby 5V is not functioning. The second step is to place a short across the AC terminals of RY601 for less than two seconds. If degauss operates then check Q601 and RY601. If degauss does not work, check TH601 for an open condition and VA600 for a short condition.
Primary Section
Three main areas can diagnose primary circuit failures. These are IC601, Q602 and Feedback system. Visible checks of these areas will aid in finding problems. The following will discuss each section.
IC601
First apply AC to the monitor and check IC601 pin 4 output. If the output on pin 4 is not present, there could be problems with Q602 and related parts or pin 14 could be less than 2.5 volts. Further, check Vaux level at pin 6. If it less than 11 volts, the IC could be in safe-restart mode. If the voltage is very low, there could be a short on any of the IC pins. In reference to ground, check the impedance of pin 1, 8 and 14. If any of these pins are shorted, replace the IC and check components connected to the related pins. Take care that C617 and C616 are fully discharged before replacing the IC.
Q602
The switching transistor can be damaged in various ways. These are related to voltage, current and temperature. Check whether the transistor is shorted across drain and source terminals. If there is a short, F601, R605, R614, R654, R623, R624 and C650 should be checked. Additional components to check are D608, R612 and IC601. If Q602 is shorted, all these parts should be replaced. Failure of a secondary rectifier diode can also cause Q602 to fail. Check 180V and 80V diodes for open or short conditions. There is also a clamp circuit, which is used to clip the turn off spike found on Q602 drain. If the clamp circuit is broken, it can cause Q602 failures. Check D606, C612 and R635. Also check the snubber circuit components C613, D607, R619 and R656.
Secondary Circuit
Failure in the secondary circuits can be categorized by rectifier diodes, fusible resistors, regulators, feedback loops and protection circuits. These sections are interrelated and failure in one can affect another. Consequently, some failures will also affect the primary circuitry.
Rectifier Section
Rectifier diode failures are not common, but do occur. Deflection, video and high voltage circuitry failures contribute to diode damage. In the event a voltage is not present, check for shorts to ground, open or short diodes. Also check fusible resistors found on the voltage lines.
Horizontal Centering
Loss of horizontal center adjustment can be affected by the rectifier diodes, fusible resistors, IC503 and related circuitry. Measure the voltages in reference to the horizontal centering ground. Typically, the voltages are ±10 volts. However, the adjustment setting can reduce the voltages. If there are no problems found with the diodes or fusible resistors, the next step is to check the adjustment signal at Q506. If the adjustment signal is not present check the IC901 pin 4. Otherwise, check IC503 and related components.
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+5/12 Volt Regulator
Loss of voltage due to shorts or device failures on either +12 or +5 volt output lines can occur. Consequently, IC605 or IC608 can be damaged and need replacing. Before replacing either IC, check for shorts or damaged parts along the output lines. If +12 volt does not appear, check the remote on/off signal from IC901 pin 6.
Standby 5V Circuit
Failure of this circuit can be affected by IC607. In case the circuit does not work properly, check D605, D614, R634, R611 and Q604. If these components are good, check the remaining circuit parts.
Heater Voltage Regulator
This circuit may be affected by fusible resistor R634 or D619. If these parts are good, check the regulator output for a short to ground. Shorts can occur on the video board. In the case of an output short, IC602 may have been damaged. If the IC appears to have no damage, check for any problems with the heater on/off signal.
Feedback Circuit
Problems with feed back can cause power supply shut down or low voltages. First determine whether the power supply is operating in active off, active on modes or not at all. The power supply can be stuck in active off mode. The remote on/off signal, Q603, Q604, D605 and IC603 can affect this condition. Likewise, if the power supply is always in active on mode, the same items should be checked. Checking for voltages at IC603 pins 1 and 2, IC604 pins 1 and 3 can solve more difficult problems. Additionally, IC603 pins 4 and 5, and IC601 pin 9 should be checked. If there are problems with these devices, 180V or standby 5V line, the feedback systems will not work correctly. Also check the protection circuits.
Protection Circuits
OCP occurs when there is excessive current through Q602. Failures with Q510, Q507 or the video section could cause this condition. These areas should be checked. OCP condition can also occur if R614 or R654 are open; if R623 is shorted; or if R624 is open. OVP usually occurs when the feedback loop is open, or loss of standby 5V. Isolate the OVP trigger condition, by first checking the operation of the feedback loop.
D BOARD DEFLECTION SECTION 1. Horizontal Deflection Circuit
Overview
These circuit drive the DY (Deflection Yoke) for Horizontal Deflection. The H size and H shape control (IC501 and around) is included in this page as well.
H Drive, H Out, Feedback
+12Vp-p HD pulse is generated by the inverter Q903 using the Jungle IC902 H. out pin #17. And switch Q511 through A push-pull amplifier (Q501 and Q502) buffers. The drive current which introduced in HDT (T504) by this switching will drive Q507 (H out Tr) and 1000V pulse appears on collector. D506 is the "Damper Diode" which avoid the negative pulse and discharge the energy for next Horizontal Drive. Q508 is the buffer for the "H BLK" feed back to Jungle IC 902 H. FLY pin #14 and it will be the reference of phase / jitter control of Jungle. HST (T505) is to sense the deflection current through DY. The voltage appeared on secondary side will be the feed back for H Size/Shape control.
H Size/Shape control
HD pulse also triggering the H Size/Shape control IC501 pin #8. IC501 is "PWM IC" and it controls H and HV B+ chopper duty. H Shape and H size information is already included and coming from Jungle IC902 E/W pin #9. It will be supplied to IC501 pin #2. H reg output pin #20 is switching pulse of Q520 (B+ chopper). The energy supplement from 180V to H Def circuit (through L503 HOT) is controlled by the duty of this pulse. The H Shape input and feedback voltage from T505 are compared by error amp (in IC501) and H Reg out pulse duty is controlled to keep the level of these two the same.
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H Deflection Circuit
C543 C563 R553 3 20 180V FB506 R581 H SHAPE HD IN IN 2 8 C582 R583 C576 D516 T504 HDT 12V 12V CN801 R933 R506 4 Q501 Q903
HD output pin #17 IC902
R551
H Def H Reg IN Out PWM IC501
E/W PIN #9 IC902
C575 12V Q518 Q520 B+CHOP 2 5 L503 HOC
TO: H Lin and Ringing Circuit 1 3 T504 HST 4 HDY3 HDY-
R569
D518 R586 R582 C574
2
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FB504 8 6
1
2 H DY+ 2 R517 R518 Q507 H-OUT D506 C518 C521 1 Q508 1 H DY+ H BLK TO IC901 #32 pin IC902 #14 pin
C502 Q511 D502 R508 R508 D501 R513 C510 R511 -16V
R594 Q502
C522
Troubleshooting
See attached "FLOW CHART" and confirm if it's really H Deflection issue.
No H Deflection / No Power
Check Q507, Q520 and D506 first. In case any of these shorted, check T504, Q511, R511 and D502. Those parts might have been damaged. If both of Q507, 520 were not broken, check the HD pulse at the gate of Q511. If no pulse, check Q501, Q502, Q903. Otherwise, check R582, D518 or try changing IC501.
Bad Distortion
Check pin#2 of IC501 and confirm that proper DC level and AC waveform. If the distortion is on only right side, check all above ("No H Deflection"). Otherwise, refer to the Troubleshooting of next section ("H Lin and Ringing Correction").
2. H Linearity and Raster/Distortion Ringing Correction Circuit
This section includes HLC Control circuit, S cap switching and HLC/S-Cap Damping circuits. These circuits are placed directly on the "cool side" of DY which is in series with deflection current line. H Centering circuit will be explained in next section.
HLC Switch Control and HLC Damping
There is HLC switch circuit. In case that Q519 is on, RY500 turn on then, L509 is shorted. Q519 is controlled by Microprocessor (IC901). D505, R577 and C581 are damping circuit to avoid the raster Ringing (mainly on left side of picture) caused by HLC, DY and S-caps.
S-Cap switching and S-cap Damping
H Def current is distorted by resonance between S-Cap and DY to correct the linearity. Since the resonance frequency has to be changed for each fH, S-Cap switching is controlled by MICRO S-Cap Switch - FETs (Q512, Q513, Q514, Q515, Q516) are "On" when its gate is Hi(5V) and that moment, drain voltage should be grounded (0V). L506, R578 and C573 is damping circuit to avoid Distortion Ringing (mainly on top of the picture) caused by S-caps and H Control loop gain. L505, R575 and C572 is also the same purpose as above but only works when Q519 (Switch for the Biggest S-Cap) is "On".
Troubleshooting
See attached "FLOW CHART" and confirm if it's really H lin issue.
Bad Linearity
Confirm that Raster is approximately in the center of the Bezel. If not, refer to next section (Raster Centering Circuit). Check S-cap switches (Q512, 513, 514, 515, 516, HLC switch (Q519)) and confirm that H Linearity changes proportional to the value of "S-Cap".
Bad Top Distortion/ Left side Raster Ringing
Check damping circuits explained above.
3. H. Raster Centering Circuit
Overview
H Centering is changed by supplying DC current to DY. D99 is taking the common level on DY cool(-) side and +/- 8V from power supply transformer(T601 PIN#16, 17, 18. #17 is the common).
H Center Circuit
The DC current is outputted by powered OP-amp (IC503). This circuit is making "invert amp" with the gain of R573/R579 and input 1S Q518 collector. The level is controlled by MICRO"H CENT" pin #4 through Q506(buffer).
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CN501 HDY - #5.6 pin
H SIZE/Shape Feedback R593 # L508 HLC
12V
3
TH502 #
2
12V
4 5
R516 150 1/2W :RN R591 150 1/2W :RN R592 150 1/2W :RN
1
R589 4.7k
L509 HLC
RY500
T505
D519 1SS119 C517 0.01 :PT R576 47k
Q519 DTC114TSA
+
D512 1SS119 C581 #
C572 4.7 250V R575 68 1/2W :FPRD
R590 22k :RN
C583 Q521 0.1 2SA1309A :PT C573 4.7 250V
D505 ERB91-02TP1
R578 39 2W :RS
R577 33 3w
:DFT T503
C514 0.82 L506 250V 820µH :PP
L505 2.2mH
H CENTERING CIRCUIT
S4
S3
S2
S1
D
(BOARD)
H. LINEARITY AND RASTER/DISTORTION RINGING CORRECTION CIRCUIT
S0
S4
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+ 5 4 3 2 1
R515 1k :FPRD R521 1k :FPRD C511 0.22 250V R512 :PP 4.7
C568 0.047 400V :PP
C516 0.3 250V :PP C531 0.068 250V:PP
C523 0.12 250V
C525 0.047 400V :PP Q515 2SK3332
C529 0.047 400V :PP Q516 2SK3332 STBY 5V
C530 0.12 250V R525 1k :FPRD
Q513 2SK2098
Q512 2SK3332 R533 1k :FPRD
R536 1k :FPRD R537 56k :RN
C507 0.19 400V
S C512 0.01 B:CHIP
R519 56k :RN
C515 0.01 B:CHIP
S
S R524 56k :RN C520 0.01 B:CHIP
R523 56k :RN
S C536 0.01 B:CHIP
R535 56k :RN
S C538 0.01 B:CHIP
Q514 2SK3332
C670 FROM D615 IN P.S. HC+ HC N R570
HC+ C580
FROM PIN #17 T601
FROM D616 IN A.S. C631
HCT120 Q518 R500
D511 R579 R571 R573 2 C559 R572 1 4 HC+
5 IC502 R538 L510
R529 R514 H CENT C506 C509 Q506
TO H. DY(-) VIA L503 (DRAIN OF Q520)
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R580
R539 3
C570
HC-
TO H. DY(-) VIA L510
!!! IMPORTANT !!!
D
(BOARD)
=
COMMON (ISOLATED) CENTER VOLTAGE
(19D99 H. CENTERING CIRCUIT)
Rotation/Vertical Key Circuit
STBY 5V
R558 +15V #1, 2 PIN IC502 Rotation Coil (CN701) R563
4
5 V+ + V- 1 2
R559 R560
C549
3
ROTATION
3
R562 R566 -15V
C547 IC901 C513
Trouble Shooting
See attached "FLOW CHART" and confirm if it's really H Center Circuit issue.
No Raster Centering Control
Check R638, 639 (Right next the SRT) first. If it's open, change IC503. Confirm that voltage of Q5l8 base is changing accordingly to "HCENT _MINFH, HCENT_LO_FBFH, HCENT_HI_FBFH, HCENT_MAXFH" register. If not, change Q506.
CAUTION!!
The heatsink of IC503 is connected to the H center(-) level, not GND! It could have up to 150V and should not be touched to any other metals.
4. Rotation Circuit
Rotation is a PWM waveform at approximately 125kHz measuring 5Vp-p at pin #3 of the micorprocessor IC901. Then filtered by R560 and C547 combination. The DC current is outputted by powered 0P-amp (IC502). The output current from pin #4 of IC502 flows through R563 and the rotation coil and returns to ground through R566. The feedback is sensed at R566 and sent back to the amplifier through R562.
No Rotation Control
Check the waveform pin #3 of microprocessor IC901 if it is 5Vp-p PWM and approximately 125kHz. Otherwise, check around IC502.
5. Dynamic Focus Circuit
Overview
Both H and V Dynamic Focus are combined through DFT (T503).
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H DF
Horizontal Parabola is injected into the secondary side of the focus transformer (DFT:T503). In order to keep the amount of parabola constant over the horizontal frequency range the values of the AC coupling capacitors are changed by the transistors, which switch the s-caps. This signal is amplified by the turns-ratio to the primary side of the transformer.
V DF
V DF waveform is buffered by Q505 and amplified by Q504 to about 150vp-p. VDF is controlled by Jungle IC902 pin #12. 300v Vcc is made by FBT through D515. This voltage is also used for HV Protector.
Troubleshooting
See attached "FLOW CHART" and confirm if it is really a DF issue.
Bad H DF
Check H. Linearity. If it's no problem, change T701, T503 (DFT).
Bad V DF
Confirm that waveform is around 1Vp-p. If it's more than 2.0Vp-p, change Jungle IC902. Check 300v from FBT from Jungle pin 12 IC902.
6. High Voltage Protect Circuit
This circuit generates the High Voltage supply for the anode and G2 (1000V) of the CRT. It consists of a high voltage driver and regulator similar to a switching power supply function. In addition, there are High Voltage and Beam Current protection circuits. All those circuits are similar to D1 chassis circuits.
High Voltage Regulation and Output Circuit
The HV Drive pulse is generated by IC501 and synchronized with Horizontal drive pulse. It is supplied to the Gate of Q510 the HV Out FET. The HV Out Pulse approximately 700V, is generated by Q510 switching with the peak voltage being controlled by the switching duty of Q503 (B+ chopper). Internal resistors and R540 and RV501 divide HV generated in the FBT. Since this voltage is the feedback for HV Regulation control. Adjusting RV501 will result in changing the HV Regulation level(= HV level). HV Feedback voltage is returned to IC501 at pin#12 to be compared with an internal reference voltage of IC501 at pin#13. According to this feedback level, IC501 changes the pulse duty cycle. This pulse is felt at pin #18 of IC501 thereby controlling the output of B+ chopper drive Q503.
G2 Voltage
G2 voltage at approximately 1250vdc is produced by the HV Out Pulse rectifying through D510, C528, D520, D521, C578 and C577. This voltage will be supplied to A board via CN 510, which contains the G2 control circuit.
HV Protect Circuit
HV Protect circuit will be activated by the Microprocessor when the signal at HV DET, Microprocessor pins#18 reaches a +5vdc level. HV DET indicates the level of the primary current developed by the 300V winding of the FBT through R543, D515.
Beam Current Protect
Beam Current Protect will be activated when ABL DET at microprocessor pin#16 reaches a level of 0V when operating in main mode. ABL DET level is corresponding to the Beam Current which is supplied to FBT through R596, R550 and R548. The voltage current relationship is inversely proportional Voltage (down) Current (up).
Troubleshooting Hints
See attached FLOW CHART to confirm if is really an HV/Protect Circuit issue.
No HV / No Power
Perform basic checks of Q510 and Q503 first. If both Q510 and Q503 were not broken, check the HV Drive pulse at the gate of Q503. If no pulse, check R534 and D509. Otherwise, check R520, D504 or try changing IC501.
No G2 Voltage
Check R532 and D510, D520 and D521.
- 15 -
Dynamic Focus Circuit
FBT
R543
D515
7
FBT
C540
6
VDF PIN #12 IC902 12V R506 330k :RN R565 330k :RN :DFT T503
6 7 8
5 4 3 2 1
R515 1k :FPRD R521 1k :FPRD C511 0.22 250V R512 :PP 4.7
R502 180k :RN-CP
R505 10k
C568 0.047 400V :PP
C516 0.3 250V :PP
C531 0.068 250V :PP
C523 0.12 250V
C509 Q506 100p 2SA1309A 500V B
Q504 2SC3941A-QR
C504 330p 500V B C505 15pF 2kV
C525 0.047 400V :PP
C529 0.047 400V :PP Q516 2SK3332 STBY 5V
S4
S3
S2
S1
TO FBT PIN #15
S0
S4
- 16 R501 100 CHIP + C501 10 R503 10k :RN-CP Q505 2SA1309A
C530 0.12 250V R525 1k :FPRD
Q513 2SK2098
Q512 2SK3332 R533 1k :FPRD
Q515 2SK3332
R536 1k :FPRD R537 56k :RN
R507 2.7k :RN C503 -15V 0.01 B:CHIP D529 MTZJ-T-77-18
C507 0.19 400V
S C512 0.01 B:CHIP
R519 56k :RN
C515 0.01 B:CHIP
S
S R524 56k :RN C520 0.01 B:CHIP
R523 56k :RN
S C536 0.01 B:CHIP
R535 56k :RN
S C538 0.01 B:CHIP
Q514 2SK3332
Protect Malfunction
To see if HV Prot or ABL Prot are suspect check the Shutdown Log data at the Shutdown Log register. Refer to Shutdown Log Table below. When an HV Shutdown is indicated, check R917, R921 and D905 or, replace T501 (FBT). Where ABL Shutdown is indicated, check the voltage T901 pin#11. If it is higher than 0.5v immediately prior to shutdown, check connections all the way to N board. Should the voltage reach and remain at the 0 volt level, even after the first 2.0 seconds of Power On, check D909 and 904 or check White Balance.
SHUTDOWN LOG TABLE Bit Register value
bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 128 64 32 16 8 4 2 1
Shutdown Mode
N/A N/A Thermal ABL Shutdown HV Over HV U Shutdown No Vertical Scan No H Scan
Comment
N/A N/A Explained later Hardware Controlled Hardware Controlled Not Used Explained later Explained later
7. Protection Circuitry Overview
Overview
The D99 chassis was developed with protection circuits other than HV/ABL.These protection circuits are controlled by Microprocessor (IC901); - Thermal Shutdown: Activates when S-Cap Switch in FET are broken (especially Q513 and Q514). - V Scan Shutdown: Activates when Vertical Deflection signal is absent or of insufficient level or of a distorted nature. - H Scan Shutdown: Activates when Horizontal Deflection signal is absent or of insufficient level or of a distorted nature.
Troubleshooting Hints S Cap Switch Shutdown
In the event of failure of any S-Cap Switching FETs, the Microprocessor detects temperature of FETs (Q513 and Q514) by TH501 and goes into shutdown mode. For these conditions, refer to the section of H Linearity Circuit.
Vertical Scan Shutdown
If the V FLY feedback at pin #19 the Microprocessor doesn't get pulse around 1.5 second, a Shutdown will be initiated. Power Supply problems may also produce a similar type failure. For these conditions, refer to the V Deflection Circuit or the Power Supply section.
Horizontal Scan Shutdown
If the H BLK feedback at pin #32 of the Microprocessor doesn't get pulse around 500mSec, Shutdown will be initiated. Some power Supply problems may also produce a similar type failure. For these conditions, refer to the H Deflection Circuit or Power Supply sections.
8. Vertical Deflection Circuit
Theory of Operation
The negative input of amplifier IC401 is driven by VSAW signal generated by Jungle IC902 pin #8. The positive input of the amplifier is Vref Signal generated by IC701 (Convergence IC) pin #5. VSAW is centered on 5. 0V, and sawtooth waveform that controls VSIZE. Vref is a reference that is compared to VSAW at IC401. VCENTER is controlled by the shift of VSAW. IC401 serves as a transconductance amplifier (it amplifies a low level voltage into a high level current) for VSAW and the DC difference between VSAW and Vref. The current gnerated by IC401 is feed to the Vertical Deflection Coil. At the return point of the Vertical Deflection Coil the current flows through R403 and R405 which generates a voltage across them which is feed back to the amplifier via R404. V FLY is generated by flyback pulse generated at pin 3 of IC401. If the flyback generation at IC401 does not work, then the
- 17 -
180V HV REG DRIVE PIN # 18 IC501 D509
R534
C527 R527 Q503 B+ CHOPPER HV
S
R561 R530 R531 C526
D513 L501 L502 FB502 T501 :FBT
2 HV
ANODE OF CRT R597 R541 R540 RV501 C539 C532 R568 C556 IC501 PIN #12 "HV FEEDBACK"
- 18 CN510
Q510 HV OUT HV DRIVE PIN # 19 IC501
S
1
13
C519 R520 D504
5
16
C534 R542
R574 C577 G2 1ku D521 C528 D517 C542 300V D515 R543 R595 R547 R549 C544 R552 R510 C540
6 10
FV1
CRT VIA RED FV LEAD SG501
R544
D520
C578
D510
R532
7
15
H DF OUT H&VDF OUT
9 14
FV2 7
HV DET PIN # 18 IC901
CRT VIA BLK FV LEAD 12V D514 C535 R548 R550 R596
11
D
12
R545
ABL DET PIN #1
BOARD
R546 C541
19 D99 CHASSIS HV/PROTECTOR CIRCUIT
R934 ABL DET PIN #16 IC901 C928
+15V +16V IC401 3 Flyback Generator 9 V+ + 0 R410 C403 6 D401 2 C404
5 Vref
IC 701 (CONV)
V- -
C409
R409
TDA8177 5 V-DY through CN501 LVDY RL 4 1 7
- 19 -
R401
C402 -15V C401 R406
R402
R404 C406
0
8 VSAW
IC 902 (Jungle)
R403 R405
D-BOARD
0
Heater and Focus Voltages from D Board
RGB Cathode Drv
Front Input
Video Process D/A Conv
J001
D/A Level
CRT
I2C Communication
Cuttoff Voltage
G2 Voltage
V Sync and H fly
OSD Generation G2,Cutoff
17 D99 Chassis A Board Block Diagram
monitor goes to be shutdown as a V scan failure by microprocessor after wait around 1.5sec w/o VFLY.
Troubleshooting Hints
Vertical Scan Failure
The first step is to check the shutdown log of the monitor and make sure the microprocessor has detected a loss of VFLY. Once this has been verified the output of IC401 should be checked. If a normal output exists after the remote on/off bit is turned on but the monitor still shuts down then the VFB detection circuit is malfunctioning. If no output exists signal tracing should begin at IC902 pin #8 (VSAW) and IC701 pin 5 (Vref). In shutdown mode both of these levels should be 5.0V DC. If the remote on/off bit is turned on a sawtooth waveform of about 1Vpk-pk should appear on VSAWN while DCC2 stays at 5.0V this should last about 1.5 seconds until a loss of VFLY is detected and the monitor shuts down again. If the signals make it this far, the problem is likely in the IC401 area.
VIDEO "A" BOARD ELECTRICAL CIRCUIT
The Main function of the A Board is to receive incoming video signals and then process them into the RGB video drives necessary for proper CRT biasing. The input signals (RGB, Separate & Composite Syncs and DDC) are received with the conventional 15 D-sub connector. The RGB signals (0.7Vpp) are sent to the preamplifier (IC001) where they are amplified with Contrast gain and Brightness offset. Next they are sent to the Video Driver for final amplication to drive the cathodes. The Horizontal Sync pulse is buffered and then sent to the Microprocessor along with the Vertical Sync pulse. DDC is no longer handled on the A Board. It passes through the A board directly to the micorprocessor. IC003 is the On Screen Display (OSD) generator. OSD mixing is performed in IC001. Additional functionalities of the A Board include processing of all the CRT cathodes operating voltages; heater, G2 control, cathode DC bias, and focus.
- Sync Timing Buffering. - RGB video signal amplification and adjustment according to white balance requirements, contrast and brightness settings. - On Screen Display mixing. - D/A conversion for RGB CRT cathode cutoff G2 levels control.
- 20 -
Video Select and RGB Process Functions
+5V
+12V IC001
+12V IC003
+80V
8
22 20 24 27
R G B
10 8 9 11
6 5 3 1
D104 C106 C206 C306 CRT
Video Input (0.7Vpp)
R G B
11 9 7
I 2 C Data 1 I 2 C CLK 2 CBLK 18 BPCLP 12 R_OSD 15 B_OSD 14 B_OSD 13 OSD_BLK 17
From N Board
From IC003
D/A Cutoff 3 Control 4 5 6 +12V IC004 2 11
10
D105 0 D106 D206 D306 +B
R G B D/A G2 Control
3 4 5
7 8 9 13
R G B
1. RGB Signal Processing (A Board)
RGB Signal Amplifiers
RGB video signals are amplified by IC001. Here the individual Sub Contrasts, Brightness offsets, and Contrast gain levels are set by the Microprocessor via I2 C control. The OSD RGB video signals from IC003 are mixed into the main video channels inside IC001. IC002 provides a final amplifier stage for the RGB video signals. This video driver is internally set to a gain of 14. Therefore at the output pins of IC002 (Pin1, 3 & 5) the waveform is inverted with typical drives levels on the order of 45Vpp. The Video Driver IC002 drives the CRT cathodes via AC coupling.
RGB Cathode Cutoff Amplifiers
The Red cathode DC cutoff level is amplified by IC004. It is controlled by the D/A output of IC001. The Red cutoff level is clamped by discharging C106 via D106. The Green and Blue cathode Cutoff levels are clamped in a similar fashion. The individual cathode cutoff levels are set for white balance by the Microprocessor via I2C communication with IC001.
Troubleshooting Hints
1) If the screen is blank with no output check: - Video signals with proper cutoff levels are provided to the CRT cathodes. - Supply voltages are at the appropriate levels and locations starting at CN305. - Heater voltage is correct and present at the heater cathode. - Diode shorts at the cathodes. - Sync timing signals are present at the output of IC006. - That there is I2C communication to IC001. 2) If the screen is lighted with no video check: - Control, blanking and clamp signals to IC001, IC002. - +5V, +12V, and +80V to these circuits. -For shorted diodes on the IC002 outputs.
- 21 -
Block Diagram IC003 OSD
7 DISPLAY MEMORY 8 6 HORD VERD CH OSD_EN SHADOW BSEN X32B VPOL HPOL 54 15 9 RFG MCLK BUS ARBITRATION LOGIC ADDRC RDATA 8 Z 32 13 ROW BUFFER NROW VPOL VFLB 10 CHS VERD 8 VERTICAL CONTROL CIRCUIT 4 LP R 4 CRADDR 6 CWS WADDR WCOLOUR and CONTROL
CONTROL REGISTERS
7 SDA(MOSI) SCL(SCK) 8 SS 6
DATA RECEIVER MBUS/SPI
8 9
DATA ADR
and DATA MANAGEMENT
32
Y
CCOLOURS and SELECT CHS
CH 6
CHARACTER ROMS HIGH RESOLUTION FONT 12 X 18
DHOR
MCLK
12 7 HORD CHAR CWS 12 BITS SHIFT REGISTERS SHADOW BSEN
RP VCO HFLB
3 2 5
HORIZONTAL CONTROL and PLL SC CCLK
WADDR
54
4 VDD(A) VSS(A) VDD 16 VSS 1
X32B
BLACKEDGE
LUMINANCE
HPOL
OSD_EN
CCOLOURS and SELECT 13
BACKGROUND GENERATOR
W WCOLOUR and CONTROL
3 15
COLOUR ENCODER
15
14
13
12
11
FBKG
R
G
B
Block Diagram IC004 Cut-off Module
Video signal (R)
+B voltage
12 V
R-bias out
2
11
7
G b l o c k
B b l o c k
Vref GND 1
Similar to R block 3
R-Cont in
- 22 -
INT
CRT cathode (R)
3) If colors are wrong or missing and white balance cannot be adjusted check: - Each individual color signal path comparing DC offset and peak to peak signal levels to each other to determine if there is any single amplifier at fault. - For shorted diodes on the IC002 outputs.
2. On Screen Display Functions
On Screen Display(OSD)
IC003 is the On Screen Display character and graphic generator. It provides RGB and Fast Blanking data to IC001 for mixing with the main video channels when required. Outputs voltages are two dimensional, either 0V or 5V. IC003 is controlled by the Microprocessor via the I2C bus. The sync timings necessary are V sync and H Fly.
Troubleshooting Hints
1) No OSD is displayed, check: - RGB and Fast Blanking inputs to IC001. If there are no signals then IC003 may be at fault. - That +5V is supplied to IC003 - V FLB and H FLB signals are at pins 10 and 5 of IC003 respectfully. - That there is I2C communication to IC003.
3. G2
G2 Amplifier
The G2 reference is provided to IC005 Pin 5 by the IC001 D/A converter. The G2 voltage at the cathode is typically 500v ~ 750V.
Troubleshooting Hints
1) If picture is black, check: - G2 level at the cathode using HV probe. - Input to G2 amp, Pin 5 of IC005. - Heater voltage at the cathode. -+12V, +5V, and G2 voltage coming from D board.
4. Display Data Channel Circuit (DDC)
For DDC2BIC007 is a serial memory device providing Extended Display Identification or EDID data that is read by the compatible Host Computer on Pin 5. The basic EDID format consist of 128 bytes which are described in the table below. The 15 Pin VGA connector allocation is also described. The compatible Host Computer provides a V CLK on Pin 7 that is derived from the V Sync input and is used to set the timing of each data reading cycle. The data is clocked by the input of IC007 Pin 6. The rear input supports DDC2Bi. The data is passed through the A Board to the Microprocessor on the N Board via CN311.
Troubleshooting Hints
1. The DDCB circuit should be checked if error DDC messages or erroneous monitor identification data is indicated by DDC2B the compliant Host Computer. Check that the V CLK and S CLK signals are input to IC007 on Pins 7 and 6. The Data transition should be visible at Pin 5.
- 23 -
DDC Data format and VGA Connector Allocations Basic EDID consist of 128 bytes Number Description 8 Bytes Header 10 Bytes Vender/Product Identification 2 Bytes EDID Version/Revision 5 Bytes Basic Display Parameters/Features 10 Bytes Color Characteristics 3 Bytes Established Timings 16 Bytes Standard Timings 72 Bytes Detailed Timing Description 1 Bytes Extenion Flag 1 Bytes Checksum
15 pin VGA type connector Pin No. Assignment 1 RED Video 2 GREEN Video 3 BLUE Video 4 Option 5 Return 6 Red Return 7 Green Return 8 Blue Return 9 Option +5V 10 Sync Return
Pin No. 11 12 13 14 15
Assignment Option Data(SDA) H SYNC V SYNC Clock(SCL)
System Block Diagram
IN VIDEO IN SYNC DISPLAY DATA COMMUNICATION BUS (DDC) HEATER DC POWER VIDEO BLOCK OSD A-BOARD
RGB VIDEO
FOCUS/G2
MAIN AC
POWER SW
I2C-BUS 1Kv
Sync
POWER SUPPLY
Deflection PS Mode
FOCUS BLOCK FBT
STATIC/ DYNAMIC FOCUS
D.CONV H&V DEFLECTI ON HV I/O
H/V DEF. TILT
JIG I/O(RS232C) D BOARD
I/O SYNC PROC.& CONTROL N-BOARD
USER CONT H BOARD
- 24 -
D IG IT A L C O N T R O L C O M M U N IC A T IO N D IA G R A M
V ID E O B O A R D H V s yn c A B O ARD P re -A M P IC 0 0 1 B IA S D R IV E CONTRAST B R IG H T G2
In fo rm a tio n fo r U S E R A lig n m e n t jig (fa c to ry ,s e rv ic e ) M ic ro p ro c e ss o r IC 1 0 0 1
I 2 C -B U S
OSD IC 0 0 3
DDC
PC (H o s t co m p u te r) D S P IC IC 0 0 2
S IZ E (Z O O M ) CENT G E O M (P IN ,K E Y .x ) C O N V .(S T A T ,D Y N A M IC ) FOCUS
U s e r c o n ro l/ P o w e r sw
E E PRO M
N BO ARD
- 25 -
GENERAL TROUBLESHOOTING
Input crosshatch from generator
No Picture
A
Missing Color or Abnormal Color
B
Visible Retrace or Visible Raster
C
Mis-convergence
D
Poor Focus
E
Unsynchronized Image
F
Abnormal Geometry
G
Abnormal Image Size
H
Shutdown
I
No Communication
J
Other Trouble
See Manager
- 26 -
NO PICTURE
A
Is amber power LED blinking?
Yes
I
No
Is amber LED on?
Yes
Check the video cable connection No
Is green power LED on?
No
Yes
Press power switch; if LED does not turn on, repair power supply (I)
Does A-Board make proper contact with CRT gun?
No Press A Board carefully to make proper contact with CRT gun
Yes Check heater, G2, red, green and blue cathode voltage levels. Repair video (12) if needed
No
Can you get picture?
Yes
Done
- 27 -
MISSING COLOR
B
Check signal generator & cable
No
Are proper video levels present on CN313 pins 2, 4 & 6?
Yes
No 12 (See Parts Level Board Repair Section)
Are proper AC voltages present on all cathodes?
Yes Are proper DC voltages present on all cathodes?
Check IC004, IC001 pins 7, 8, 9 and +B voltage
No
Yes Check IC005, G2 control, circuit, IC001 pin 6 and FBT
No
Is G2 voltage correct?
Yes Change the CRT
Done
- 28 -
VISIBLE RETRACE
C
Check white balance adjustment
Check IC005, G2 control circuit, IC001 pin 6 and FBT
No
Is G2 voltage correct?
Yes
Check FBT signal at IC901 pin 46
No
Is blanking pulse present on pin 18 of IC001 on A-Board? Yes
Check IC001 and related components
No
Is blanking pedestal present in the waveforms at pins 20, 24 & 27 of IC001?
Yes
Check IC002 and IC004
No
Is blanking pulse present on all cathodes?
Yes
Done
- 29 -
MISCONVERGENCE
D
Reset using front panel control
Try adjusting convergence using front panel controls
Try adjusting convergence using DAS
No
Is the convergence now within spec?
Yes
Done
Yes
Is the convergence within spec?
No
Check the convergence circuit (IC701 & IC702 & IC703)
Yes Change DY and readjust convergence Is the convergence circuit (IC701, IC702, IC703) OK?
No Yes Is convergence within spec now? Repair & adjust
No Change CRT & readjust convergence
Done
- 30 -
POOR FOCUS
E
Adjust focusVRs
Age monitor and check for focus change
Yes
Improved focus?
No Check focus leads from FBT to CRT socket
Check CRT socket
No 11
Is dynamic focus circuit OK?
(See Parts Level Board Repair Section)
Yes Replace CRT and verify focus
Done
- 31 -
UNSYNCHRONIZED IMAGE
F
Check input signals CN313 pins 4, 8 and 9
Check video cable
No
Are signals correct?
Yes
Check sync separation circuits on video board
No
Signals at CN309 pins 4, 5 and 7 OK?
Yes
Check wire dressing and connections
No
Signals at CN903 pins 4, 5 and 7 OK?
Yes Check circuits on D-board (IC901 and IC902)
Done
- 32 -
ABNORMAL GEOMETRIC DISTORTION
G
Download factory settings
Identify distortion problem and repair (See Board Level Repair Section)
No
Is geometric distortion correct?
Yes
Done
- 33 -
ABNORMAL IMAGE SIZE
H
With user controls adjust picture size
5
No
Horizontal size adjustment OK?
(See Parts Level Board Repair Section) Yes
4 or 5
Yes
Vertical size adjustment OK?
(See Parts Level Board Repair Section) Yes
Adjust monitor
Done
- 34 -
SHUT DOWN
I
Check power supply
No
Is amber LED blinking?
Yes Check shutdown log in IC901
Check horizontal, vertical deflection system and check power supply secondary voltages
Yes
Scan failure?
No
Check high voltage system
Yes
High voltage failure?
No
10 (See Parts Level Board Repair Section)
No
ABL OK?
Yes Set factory settings inside IC901
Done
- 35 -
NO COMMUNICATION
J
Correct connection
No
Are connections to monitor OK?
Yes
Correct settings and connections
No
Are computer settings and connections OK?
Yes
Check Connector and power supply
No
Is 5 volts present at CN901 pin 2?
Yes Check IC901 and related components
Done
- 36 -
PARTS LEVEL BOARD REPAIR
Parts Level Board Repair
(1) Power Supply
(2) Horizontal Deflection
(3) High Voltage
(4) Vertical Deflection
(5) Horizontal Size
(6) Horizontal Center
(7) Key and Pin
(8) Key and Pin Balance
(9) Rotation
(10) ABL
(11) Dynamic Focus
(12) Video
(13) Convergence
- 37 -
POWER SUPPLY
1
Check F601 and D601
Check R627, Q503 Q510, Q520, Q507, and video board
Yes
Does power supply make chirping noise?
No Check IC602, IC603, Q503, Q510, R614, R654, R623, R624, D605, Q604, R627, Q520, Q507 Check for overload on IC607
Yes
Tries to start?
No Replace Q602, Check F601, R654, R623, R624, C650, R612, IC601, D608, R605 and R614
No
Q602 OK?
Yes
Replace parts, verify voltages
No
Are F601, D608, R605, R614, R654, R623, R624, R612, C650, IC601 OK? Yes
Check secondary diodes, FPRD resistors, IC501, IC901, IC902, IC605, IC401, IC607, IC608
Check A board; if OK, replace D board
No
Operating
Yes Verify voltages and adjust monitor
Done
- 38 -
HORIZONTAL DEFLECTION
2
Check IC901 and related components
No
Is IC901 pin 27 output OK? (H-USYNC)
Yes
Check IC902 and related components
No
Is IC902 pin 17 output OK? (H. Out)
Yes
Check Q501, Q502 & R504
No
Is Q501 emitter output OK?
Yes
Replace and check related circuitry
No
Is Q511 OK?
Yes
Replace and check related circuitry
No
Is T504 and FPRDs OK?
Yes
Replace and check related circuitry
No
Is Q507 OK?
Yes 3
- 39 -
HIGH VOLTAGE
3
Replace Q503, D509 and check related components
No
Is Q503 OK?
Yes
Check Q510, Q503 and related components
No
Are Q510, Q503 and related components OK?
Yes
Check IC501 and related components
No
Is IC501 pins 18 &19 output OK?
Yes
Resolder if necessary
No
Is soldering or mount around RV501, C532 OK?
Yes Change FBT, verify operation and adjust monitor
Done
- 40 -
VERTICAL DEFLECTION
4
Check power supply
No
Are +15V and -15V OK?
Yes Are IC902 pin 8 (VSAW), IC701 pin 5 (VrefOut) & IC401 pin 3 waveforms OK?
Check IC902 & IC701
No
Yes
Verify IC401 and verify
No
Is IC401 OK?
Yes
Change DY
Adjust monitor
Done
- 41 -
HORIZONTAL SIZE
5
Check if IC501, Q503 & Q510 OK
Yes
Are horizontal and vertical size large?
No
Check Q520 and check related components
No
Is Q520 OK?
Yes
Check IC902
No
Is IC902 pin 9 (E/W) output OK?
Yes
Repair H. Lin/ringing correction circuit
No
Is H Linearity OK?
Yes
Check IC501 and related components
No
Is IC501 pins 18 & 19 output normal? (Q503 Drive)
Yes Check T505 and related components
Done
- 42 -
HORIZONTAL CENTER
6
Check IC901
No
Is pin 4 (HCENT) of IC901 working OK?
Yes Check IC503 OK? No
Check D615, D616
No
Are voltages at D615 and D616 OK?
Yes Replace IC503 Yes
Replace corresponding parts & adjust monitor
No
Are Q518 and Q506 and R529 OK?
Check related components or FRU
Yes Done
- 43 -
KEY AND PIN
7
Check IC902
No
IC902 pin 9 (E/W) outputs normal?
Yes
Check IC501 and related components
No
Are IC501 and related components OK?
Yes
Check Q520 and related components
Done
- 44 -
KEY AND PIN BALANCE
8
Check IC901
No
Check if IC902 pin 18 output OK?
Yes
Check related circuit components; fix and adjust monitor
Done
- 45 -
ROTATION
9
No Check for shorts, check power supply and check IC502 +15V and -15V Normal?
Yes
No Replace IC502 and adjust monitor IC502 OK?
Yes
Check rotation coil and connections
Done
- 46 -
ABL FAILURE
10
Check IC901 ABL register settings
Readjust and verify
No
Is white balance adjustment OK?
Yes
Check high voltage circuits
No
Is anode voltage correct? (27 kV)
Yes Check if R546, R545 and FBT related circuit OK? Yes
Check IC901, FBT and related components
No
Is IC901 pin input voltage OK? (ABL)
Yes
No
Yes
Replace parts & verify Replace CRT and verify ABL No Is CRT OK?
Yes Replace D board and verify
Done
- 47 -
DYNAMIC FOCUS
11
Check IC902
No
Is IC902 pin 12 output normal? (V. Focus)
Yes
Replace and adjust monitor
No
Are Q504, Q505 and related components OK?
Yes
Replace and adjust monitor
No
Are T503 and related components OK?
Yes Check connection to FBT and to Video board
Done
- 48 -
VIDEO
12
Check connector CN306, IC901 & +5V
No
Check if I2C bus pins 1 & 2 of IC001 OK?
Check signal in
No
Check if CN313 pins 2, 4 & 6 OK?
Yes Check IC001 and HV Check if IC001 pins 20, 24 and 27 OK?
No
Yes
Replace parts & verify
No
Check if IC002 pins 1, 3 & 5 OK?
Yes
Check IC004 and +B
No
Are cathode DC levels correct?
Yes
Check IC005, G2 control circuit and FBT
No
Is G2 voltage correct?
Yes Change CRT
Done
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CONVERGENCE
13
Change "CONV-OFF" REGISTER to "0" and adjust monitor
No
Check "CONV_OFF" Register is "0"
Yes Check IC701, IC605 outputs and +15V power supply Check if IC701 outputs pins 8, 9, 6 and 7 are OK?
No
Yes Check IC702 and IC703 +15V & -15V line power supply Check if IC702 outpins 1, 6, and IC703 output pins 2 and 8 are OK?
No
Yes
Replace connector and related components
No
Check CN701 connector if OK?
Yes
Yes
Replace DY and verify if OK?
No Change CRT
Done
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Sony Corporation
9-978-862-01 Sony Technology Center Product Quality Division Service Promotion Department
English
99JJ74183-1 Printed in USA © 1999
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