Checking The Back Light Unit - Acer AL1702 Service Manual

3. Checking the back light unit

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