-42-
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 TPB1, TPB2, TPG1, TPG2,
TPR1, TPR2.
Check PSIG signals at test points TPPSIG and TPZPSIG.
Check power supply circuit 15.5V and peripheral circuit.
Check ICs IC501, IC531, IC561, IC2501, IC2531, IC401, IC301 and
peripheral circuits.
Check DVI interface stage;
Check IC201<A/D Conversion> and peripheral circuit.
Check DVI selection signals, PW_SCL1 and PW_SDA1.
No picture with PC1[DVI
digital] input source
No picture with PC1 [DVI
analog] input source
Check PC source selecting stage;
Check IC3061<RGB buffer> and peripheral circuit on the DVI board.
Check IC1201<PC1/PC2 RGB SW> and peripheral circuit.
PC1/PC2_SW5 signal (PC1: L) is output from pin 15 of IC2323<D/A>
and applied to pin 26 of IC1201 through IC5371<Buffer>.
Check PC source selecting stage;
Check IC221<Sync sw> and peripheral circuit on the AV board. Check
MNTOUT_SW5 signal (PC2-Monitor-Out:H) is output from pin 16 of
IC2323<D/A> and applied to pin 1 of IC201 and pins 9, 10, 11 of IC221
on the AV board through IC5371<Buffer>.
Check IC1201<PC1/PC2 RGB SW> and IC5311<PC1/PC2 SYNC-
SW> and peripheral circuit.
PC1/PC2_SW5 signal (PC1: L) is output from pin 15 of IC2323<D/A>
and applied to pin 26 of IC1201 through IC5371<Buffer>.
No picture with PC2 [VGA
analog] input source
Check PC/AV source selecting stage and processing stage;
Check IC5201<RGB/COMP-SW> and IC201<A/D Conversion> and
peripheral circuit.
PC/AV_SW5 signal (PC: H) is output from pin 13 of IC2323<D/A> and
applied to pins 10,11 of IC5301 through IC5371<Buffer>.
COMPO5 signal (PC: H) is output from pin 14 of IC2323<D/A> and
applied to pin 26 of IC5201through IC5371<Buffer>.
No picture with all of
computer input sources
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Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
Check following steps.
