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Troubleshooting
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No Picture
Check signal processing stage and LCD driving stage;
Check RGB S&H signals at test points TPPANELR, TPPANELG,
TPPANELB.
Check LCCOM signals to LCD panels for common center.
Check power supply circuit 15V and peripheral circuit.
Check ICs IC501, IC1501, IC2501, IC401, IC301, IC5201, IC4201 and
peripheral circuit.
No picture with "INPUT
2/3" Computer Analog
RGB input source
Check PC source selecting stage;
Analog RGB signals from input 2/3 are selected at IC4001(RGB_SW
IC) and sent to IC1201 via IC4041 (Buffer IC).
Analog RGB signals are selected at R/G/BIN1 of IC1201(PC/AV_SW
IC) and sent to IC2201.
PC_ENB signal is applied on IC1201, output from pin 17 of IC1803.
--> Check RGB signals at test points TP-RIN/GIN/BIN.
H/V sync signals named HS_PC/VS_PC are sent to IC301(Scaler IC)
through IC4001 and IC5301(Sync sep. IC).
GREF_PW (stabilized in IC301) and VS_PC signals are sent to
IC1201 and H/V_AD signals are sent to IC2201.
Sync-on Green signal is sent to IC5301, sync separated signals are
output from IC5301 and sent to IC301. The following stage is the
same route as above.
--> Check sync signals named HS_PC, VS_PC, GREF_PW and sync
signals at TP-H/V_AD.
Yes
Yes
No
No
Check following steps.
Yes
No
Check DVI source processing stage;
DVI signals are sent to IC2201(DVI & A/D converter IC) and decoded
to RGB digital signals.
At RGB(AV HDCP) mode, IC2201 reads the HDCP keys in IC8161
(EEPROM in which key selection vector is stored) and it decodes the
DVI stream encrypted video.
--> Check IC2201 and peripheral circuit and 5VDVI power supply.
No picture with all of
input sources
No picture with "INPUT 1"
RGB(PC Digital) and
RGB(AV HDCP) input sources
Check AV source selecting stage;
Component signals (Y,Pb/Cb,Pr/Cr) from input 3/4 are selected in
IC5001.
Component signals (480i/575i format) are sent to IC3101 for
video/chroma processing, and then sent to IC6201 (Sharpness IC).
Component signals (the other format) are sent to IC6201.
Component signals from IC6201 are sent to IC1201 and selected at
R/G/BIN2 of IC1201 and sent to IC2201.
--> Check component signals at test points TP-RIN/GIN/BIN. Check
IC4001, IC3101, IC6201, IC1201, IC2201 and peripheral circuit.
Sync signals signals (480i/575i format) are output from IC3101 and
sent to IC1201 via IC6301(Sync sep.).
Y_SYNC signal (the other format) is output from IC5001 and sent to
IC6301, sync separated signals from IC6301 are sent to IC1201.
H/V_AD signals output from IC1201 are sent to IC2201.
--> Check sync signals at test points TP-H/V_AD.
Yes
No
No picture with "INPUT
3/4" Y,Pb/Cb,Pr/Cr
Component input source
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