Casper 19CSPR, Service Manual

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19 ″ LCD Color Monitor Casper 19CSPR
35
8.2.2 Power Board
No power
Check AC line volt 100V or 240V
Check AC input
Check the voltage of C905 (+)
Check bridge rectified circuit and F901 circuit
Check start voltage for the pin3 of U901
Check R904, R905, R906, Change U901
NG
Check the auxiliary voltage is bigger than
10V and smaller than 20V
1) Check U901
2) Check D900, D901 circuit
OK
OK
NG
Check Q903/IC903/IC904/ZD921/ZD922
OK
Check U901 pin8 PWM wave
OK
Check U901
NG
OK
NG
NG