Sharp LL-153A, Service Manual

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