Sharp LL-153A Service Manual page 32

15" LCD Color Monitor
8.2.3 Power/Inverter Board
1.) No power
Check CN902 pin5, 6 = 12V
OK
Check AC line volt 120V or 220V
OK
Check the voltage of C905(+)
OK
Check start voltage for the pin3 of IC901
OK
Check the auxiliary voltage is bigger than 10V
smaller than 20V
OK
Check IC901 pin8 PWM wave
OK
Check Q903,R918, R919, R928,T901,ZD905,D901
NG
Check Interface board
NG
Change AC input
NG
Check bridge rectified circuit and F901 circut
NG
Change R909,R910,R931 and Change IC901
NG
1) Check IC901
2) Check ZD901, R915,C916...OVP circuit
NG
Check IC901
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Sharp LL-153A