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AMSTRAD STV 2100 N
Adjustments
Test Equipment: VIF Sweep Generator; SIF Sweep Generator; Colour Bar/Dot/Cross Hatch Generator; DC Power Supply (14V); Oscilloscope; Vacuum Tube Voltmeter; Volt Ohmmeter; High Voltage Meter; Ampere Meter (0.5 Class, DC 3mA Max.) Demagnetizing Coil; Philips Pattern Generator; Frequency Counter; Continuous Waveform Generator. (See TV Section Table opposite). COLOUR PURITY ADJUSTMENT (SEE FIG.7) BEFORE ALL ADJUSTMENT DESCRIBED BELOW ARE ATTEMPTED, V-HOLD, H-HOLD, V-HIGH, B+ VOLTAGE AND FOCUSING ADJUSTMENT MUST BE COMPLETED.
SAT SECTION
1
CONVERGENCE ADJUSTMENT (SEE FIG.7) 1. Receive a dotted pattern. 2. Unfix the convergence magnet damper and align red with blue dots at the center of the screen by rotating (R,B) static conver gence magnets. 3. Align Red/Blue with green dots at the center of the screen by rotating (RB-G) static convergence magnet. 4. Fix the convergence magnets by turning the damper. 5. Remove the DY wedges and slightly tilt the deflection yoke horizontally and vertically to obtain the good overall covergence. 6. Fix the deflection yoke by wedges. 7. If purity error is found, follow "PURITY ADJUSTMENT" instructions.
TV SECTION STEP 1). FUNCTION Tank Coil Adjustment. SIGNAL IN VIF Signal Generator. Tuner Test point Tp & tuner case (Earth). SIGNAL OUT Oscilloscope TP601 & Earth. METHOD Adjust AGC bias voltage for maximum amplitude of waveform. Adjust the output level of VIF sweep Generator to achieve 2Vp-p output on oscilloscope. Adjust T103 to obtain maximum amplitude of response at PC (39.5 MHz). Connect resistor 100 Ohm between TP102 & TP103. Adjust AGC bias voltage for maximum amplitude of waveform. Adjust the level of sweep Genetator to achieve 2Vp-p output Increase the output level of sweep generator in 20dB. Adjust AGC bias voltage to achievf 2Vp-p output Adjust tuner connvert for coil to ortain the waveform shown. Adjust the output level of VIF Signal Generator. for maximum amplitude waveform without saturation, adjust Ti 02 to obtain frequency response as shown in the fig., at 39.5MHz. Connect the TP101 (AGC) to Earth. Set the frequency of FM signal generator 6MHz with 400Hz 25KHz deviation and signal output level to 100dB. Adjust T105 to obtain the maximum output. Connect Voltmeter to TP405 and Earth. Adjust VR901 to read DC 106.5V ± 0.5V. Set the TV to AV mode, connect the Frequency counter between IC302 Pin 41 and Earth. Adjust VR303 (H.FREQ.) to the reading 15330 ± 30Hz. and back to TV mode. Receive Monoscope Pattern, adjust VR301 (H.CEN) con trol to obtain a normal picture. Set the TV to AV mode, connect the Frequency counter between V-Deflection York and Earth, adjust VR304 (VHOLD) to the reading 44Hz + 2-0 Hz, and back to TV mode. Receive Monoscope Pattern, adjust VR401 (V-HIGH) con trol to obtain a normal picture. Set screen control to min.turn R.G.B. VR501, 502, 503 and dry. VR504, 505 to mid. position. Turn the Sub-Brightness (VR305) control to mid. position, then set the Contrast control and Brightness control to MID position. Connect jumper wire between TP401 and TP402. Turn screen control clockwise until dim line appears. Then adjust VR501 to get a red H. Line, then adjust VR502 to get yellow line & then adjust VR503 to get white line. Desconnect the jumper wire, after white BALANCE adjustment. Adjust VR504,VR505 to obtain a unform width picture. Set Contrast control max. Brightness to mid position. Adjust Focus Control to get sharpest picture. Set input signal level to 62dB ± 3dB. Adjust RF AGC (VR1 01) control to the point where noise is disappeared. Set Colour control to max. and Contrast control to mm. Connect Oscilloscope to TP406. Adjust CT301, VR302 & T301 to obtain as Fig. Select Grey Scale. Set Brightness, Contrast & Colour settings to mid position. Adjust VR305 control until 10th step of the GREY Scale just appear on the screen. Press the Volume up/down key. Adjust T601 (OSD CEN.) for adjust the lettering to center of CRT. Select a teletext page, short Pin 22 of IC801 to GND. Adjust CT801 until the frequency counter reding 6.0HMz ± 0.2 KHz. Adjust T104 to obtain minimum amplitude. Refer Fig.6. Refer Fig.5. REMARKS
AMSTRAD STV 2100 N
1.Place the TV receiver facing NORTH or SOUTH. 2. Plug in TV receiver and turn in on. 3. Operate the TV receiver over 30 minutes. 4. Fully degauss the TV receiver by using an external degaussing coil. 5. Receive a crosshatch pattern and adjust the static convergence, control roughly. 6. Loosen the clamp screw of the deflection yoke and pull the deflection yoke towards you. 7. Fully turn the red and blue Drive (VR504, VR505) controls counter-clockwise. 8. Adjust the purity magnets so that green field is obtained at the center of the screen. 9. Slowly push the deflection yoke towards bell of CRT and set it where a uniform green field is obtained. 10.Tighten the clamp screw of the deflection yoke.
Refer Fig. 1 & Fig.2. Supply DC +12.5V to + TP402. (Step 1 to 4 only) Supply RF AGC bias Voltage to TP101 refer Fig 1a (Step 1 to 3 only)
2).
VIF Adjustment.
VIF Signal Generator.
Oscilloscope TP601 & Earth. Tuner Test point Tp &tuner case (Earth).
Refer Fig.3. Disconnect 100 Ohm resistorafter satisfactory results.
3). STEP FUNCTION 19). Decoder adjustment. SIGNAL IN supply Power On. Pin 6. SIGNAL OUT Voltmeter at CN104 METHOD Connect Decoder Board at CN104. Adjust VR103 to obtain 5V, 12.5V, iSV & 21V ± 2.5% Vpp output and 5V ± 5% Vcc output during ISO test. REMARKS Refer table 1. Connect Decoder Board TPWO3 to GND before Power On. 20). AFC alignment. Power On. Voltmeter at TP2. Adjust VR102 to read 2.9-3V. Tuner without signal I/P & loading. 4).
AFC Alignment
VIF Signal Generator. Tuner Test point Tp &tuner case (Earth). SIF Signal Generator TP604 & Earth.
Oscilloscope TP107 & Earth.
Refer Fig.4.
SIF Alignment
Oscilloscope TP603 & Earth.
Disconnect the TP101 (AGC) to Earth after satisfactory results.
5).
B+ Adjustment
Power On.
AVO Meter.
21).
LNB supply alignment.
Power On.
Voltmeter at Tuner LNB input
Connect 430hm resistor to LNB input Connect TP1 to GND and power on. Press SEQ key twin and press select + / - key to select V-polarization. Press PRESET key twin until the turning bar appear. Press SELECT + / - key to adjust LNB voltage to 13.1V ±0.1V. Press SEQ key and SELECT + / - key to select Hpolarization. Press PRESET key twin until the turning appear. Press select + / - key to adjust LNB voltage to 17.5V + 0.1v.
6).
Horizontal Circuit Signal Generator. Adjustment
Frequency counter IC302 Pin 41 & Earth.
7).
Vertical Circuit Adjustment
Signal Generator.
Frequency counter V-DEFLECTION YORK and Earth.
22).
SIF alignment
RF signal Generator.
VTVM and distortion meter at Pin 1 & 3 of SAT SCART.
Received the correct RF program & Audio channel. Adjust T101 to max. level output and mm. distortion output of pin 3 of SAT SCART. Adjust T102 to max. level output and mm distortion output of pin 1 of SAT SCART.
Preset Audio mode to stereo and Audio freq. L to 7.02 MHz and Audio freq. R to 7.20 MHz of RF signal generator. Preset Audio deviation to 100kHz pp. 8). White Balance Adjustment Receive a black and white picture signal. Screen.
23).
Video DEV. alignment.
RF signal Generator.
Oscilloscope at Pin 19 of SAT SCART.
Received the monoscope pattern. Press SEQ key and PRE select +/- key to select 16 MHz Video Deviation. VR101 to output 1 VPP.
Connect 75 Ohm reAdjust sistor between GND to pin 10. pin 12 and pin 19 of SAT SCART. 9). Focus. Signal Generator. Screen.
TABLE 1
Recommended Safety Parts
Item
IC902 L905 T401 T402 T901 L904
10). BW01 pin : Description ISO test no. 1. 2. 3. 4. 5. 6. 7. 8. 9. 8/9 Vcc 6/11 Res. 4/13 Ck. 2/15 D.Ck. 5/12 Vpp 3/14 Date 11). 5V 0V 5V 5V 5V 5V 5V 5V 0V 5V 0V 0V 0V X X X X 0V 3.5MHz 0V 0V 0V 7MHz 5V 0V 0V X X X X X X X X 0V 0V 5V 0V 12.5V 15V 21V *0/12.5V *0/15V *0/21V 0V 5V 0V 5V 5V X X X X 0V
RF AGC.
Signal Generator.
Screen.
Part No.
253327 241913 241671 241691 241929 241865 241928 241917 241506 241692 174811 176462 242036 253610 176754 271426
Description
IC TLP621 Opto Coupler Coil Degauss 89T 21" Tx Hori Drive AT-19E-R0710 Tx Flyback 20" CF0341 Tx Switching EI-49 T49210-130-3-5 Line Filter ELF18D615G 39mH CRT Socket 660063 AC Line Cord Black PTC Thermister ZPB53BL200C CRT 21' A51JSW90X10 220pF 500V 680pF 500V 1200pF 500V 1200pF 2KV 0.0022µF 400V 0.0022µF 500V 0.0022µF 2KV 0.0047µF 500V 0.0056µF 2KV 1µF 160V 10µF 250V 150µF 200V 220µF400V 820pF 125V 0.047µF 200V 0,056µF 200V 0.33µF 200V 0.047µF 250Vac
Colour DE Mod Adjustment
Signal Generator.
Screen.
12).
Sub Brightness Adjustment
Signal Generator.
Screen.
TH901 C423,426, 918-922 C430 C504-506 C420 C916 C413,414 C421,914 C415 903,906 C507 C412 C431,509 C428,925 C907 C121 C422 C429 C411 C904,905
13).
On Screen Adjustment. Teletext PICTURE Adjustment.
Signal Generator.
Screen.
Remark: "X" indicates don't bother to check. "*" 1 kHz Square wave.
14).
Receive a pattern with teletext signal. Receiver a colour bar pattern with nicam signal. Receiver a colour bar pattern with stereo signal L=1KHz, R=1KHz
Frequency counter TP801 & Earth.
15).
Nicam sound alignment.
Oscilloscope TP604 & Earth
272638 241711 272870 130106
16).
Nicam Sound balance alignment
VTVM. L and R Audio output (RCAsocket)
Connect 1K Ohm resistor between L A-OUT AND EARTH. R. A-out and earth. Adjust VR001 until meter reading of L. and R. output are equal.
253611
Adjustments / Safety Parts / TV Diagram / VIF, Nicam, Text, AV Switch, Handset & CRT PCB Diagram / Satellite Diagram
AMSTRAD STV 2100 N
2
Satellite Diagram Adjustments Cont'd
Fig. 1
Fig. 1a
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Adjustments / Safety Parts / TV Diagram / VIF, Nicam, Text, AV Switch, Handset & CRT PCB Diagram / Satellite Diagram
AMSTRAD STV 2100N
3
TV Diagram
Adjustments / Safety Parts / VIF, Nicam, Text, AV Switch, Handset & CRT PCB Diagram / Satellite Diagram
AMSTRAD STV 2100 N
4
VIF, Nicam, Text, AV Switch, Handset & CRT PCB Diagram & Waveforms
Adjustments / Safety Parts / TV Diagram / VIF, Nicam, Text, AV Switch, Handset & CRT PCB Diagram / Satellite Diagram