Service manual

Page 15
AL1702
3. Checking the back light unit
Is +12V supplied to inverter PWB ? (by
the power board)
OK
NG
Failure Point
1) Inverter cable disconnection.
2) Power board failure.
Check the BKLT_EN signal of the
rectangle input P301 pin 6 at TTL high
level.
OK
NG
Failure Point
1) printed wire broke between P301 pin6,
R306 and I307pin 31.
2) I307 is failure.
Check the BKLT_ADJ signal of the input
P301 pin5 from I305 pin73 is a PWM
signal.
OK
NG
Failure Point
1) printed wire broke between P301 pin5,
Q301, Q302 and I305 pin73.
2) I305 is failure.
Failure Point
Back light unit of LCD module is failure.