Sanyo PLC-XU101, Service Manual

Page: 54 / 108

-54-
Troubleshooting
No Picture
No picture with all of
input sources
Check signal processing stage and LCD driving stage;
Check RGB S&H signals at test points TP35B, TP35G, TP35R1.
Check power supply circuit 15.5V and peripheral circuit.
Check ICs IC501, IC531, IC561, IC501, IC531, IC561, IC401,
IC301 and peripheral circuits.
Check PC1/PC-switching stage;
Check IC501<PC1/PC-SW> and peripheral circuit.
PC1/PC_SW signal (PC: H) is output from pin 348 of
IC301<Scaler> and applied to pin 6 of IC501.
PC1:L, PC:H
No picture with Pc1
[Analog] input source
only
No picture with Pc2
[Analog] input source
only
Check PC1/PC-switching stage;
Check IC501<PC1/PC-SW> and peripheral circuit.
PC1/PC_SW signal (PC: H) is output from pin 348 of
IC301<Scaler> and applied to pin 6 of IC501.
PC1:L, PC:H
Check PC/AV source selecting stage and processing stage;
Check IC501<PC1/PC_SW> and IC301<Scaler> and peripheral
circuit.
No picture with all of
computer input sources
Yes
Yes
Yes
No
No
No
No
Check following steps.
Check AV source selecting and decoding stage;
S-Video source
Check S-video signal (Y/C).
S-C signal is applied to pin 65 of IC301<Scaler>, and S-Y signal is
applied on pin 64 of IC301.
S_SW signal (S-VIDEO:L) is input to pin 67 of IC301<Scaler>.
Component video source
Check component signal (Y/Cr,Pr/Cb,Pb).
The component signals are applied to pins 410, 408, 411 of IC301
<Scaler>.
Composite video source
Check composite video signal (Video).
The composite video signal is applied to pins 6 of IC301 <Scaler>.
No picture with video
input sources
Yes