
19" Wide LCD Color Monitor
Optima L903A
38
8.2.2 Power Board
1. No Power
Check to CN902 Pin1, 2 =12V and Pin3, 4 = 5 V
OK
Check Interface board
Check AC line volt 120V or 220V
Change F901, Check BD901, Q903, IC901
Check the voltage of C905 (+)
Check bridge retified circuit
Check start voltage for the Pin6 of IC901
Change IC901
OK
Check the auxiliary voltage is smaller than 20V
OK
NG
No power
NG
NG
OK
NG
Check D908, D909, ZD903…
Check IC902,IC903
Check Q903…OLP circuit
NG
OK
Summary of Contents for L903A
Page 13: ...19 Wide LCD Color Monitor Optima L903A 13 4 3 2 Optical Characteristics...
Page 19: ...19 Wide LCD Color Monitor Optima L903A 19 6 Schematic 6 1 Main Board...
Page 20: ...19 Wide LCD Color Monitor Optima L903A 20...
Page 21: ...19 Wide LCD Color Monitor Optima L903A 21...
Page 22: ...19 Wide LCD Color Monitor Optima L903A 22...
Page 23: ...19 Wide LCD Color Monitor Optima L903A 23...
Page 28: ...19 Wide LCD Color Monitor Optima L903A 28 7 PCB Layout 7 1 Main Board...
Page 29: ...19 Wide LCD Color Monitor Optima L903A 29...
Page 30: ...19 Wide LCD Color Monitor Optima L903A 30...
Page 31: ...19 Wide LCD Color Monitor Optima L903A 31 7 2 Power Board...
Page 32: ...19 Wide LCD Color Monitor Optima L903A 32...
Page 33: ...19 Wide LCD Color Monitor Optima L903A 33 7 3 Key Board 7 4 Audio Board...
Page 42: ...19 Wide LCD Color Monitor Optima L903A 42 10 Monitor Exploded View...