No Picture - Panasonic PT-TW230U Service Manual

Troubleshooting

No picture

Check following steps.
No picture with all of
input sources
No
No picture with PC1
input source only
No
No picture with PC2
input source only
No
No picture with all of
computer input sources
No
No picture with video
input sources
Yes
Check the supply voltage and LCD driving stage;
Check power supply circuit S16V_PNL and peripheral circuit.
Check ICs IC501, IC531, IC561, IC401, IC301 and peripheral cir-
cuits.
Yes
Check IC301<Scaler>, IC5301<HV Sync SW> and peripheral circuit.
R1, G1, B1 signals are applied at pins 82, 260, 258 and HS1, VS1
signals are applied at pins 331, 161 of IC301.
Check S5V and S-7V supply voltages.
Yes
Check IC301<Scaler>, IC5301<HV Sync SW> and peripheral circuit.
R2, G2, B2 signals are applied at pins 172, 78, 256 and HS2, VS2
signals are applied at pins 253, 66 of IC301.
Check S5V and S-7V supply voltages.
Yes
Check PC/AV source selecting stage and processing stage;
Check IC301<Scaler> and peripheral circuit.
Check S5V and S-5V supply voltages.
Yes
Check AV source selecting and decoding stage;
S-Video source
Check S-video signal (Y/C).
S_CHROMA signal is applied to pin 265 of IC301<Scaler>, and S-Y
signal is applied on pin 264 of IC301.
Composite video source
Check composite video signal (Video).
The composite video signal is applied to pins 262 of IC301 <Scaler>.
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