Casper 19CSPR Service Manual page 35

19" LCD Color Monitor
8.2.2 Power Board
No power
Check AC line volt 100V or 240V
OK
Check the voltage of C905 (+)
OK
Check start voltage for the pin3 of U901
OK
Check the auxiliary voltage is bigger than
10V and smaller than 20V
OK
Check U901 pin8 PWM wave
OK
Check Q903/IC903/IC904/ZD921/ZD922
NG
Check AC input
NG
Check bridge rectified circuit and F901 circuit
NG
Check R904, R905, R906, Change U901
NG
1) Check U901
2) Check D900, D901 circuit
NG
Check U901
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Casper 19CSPR