HP L1902 Service Manual page 34

2.) W / LED , No Backlight
Check CON1 Pin1 =12V
Check ON/OFF signal
Check IC201 pin5&Pin3=5V
Check the pin7 of IC201=2.5V
Check OVP LOOP (Pin2 of IC201)
Check FB LOOP(Pin9 of IC201)
Check Pin17 or Pin18 RC OSC LOOP
Check Q204/Q208/Q209/Q210
Check connecter or lamp
OK
OK
OK
OK
OK
OK
OK
OK
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NG
Check adapter or MB
NG
Check Interface board
NG
Change Q205,Q207,Q206,ZD203
NG
Check IC201
NG
CheckD201,D203,D206,D209,R223,C240
NG
Check R202,D204,D207,D110,R210,R215,
R227 R234,R222,R221
NG
Change R217/C220
NG
Change
HP L1902 Service Manual