Checking The Back Light Unit - Acer H15AAX Service Manual

3. Checking the back light unit

OK
Check the INV_EN signal of the rectangle input I307 pin 5 at TTL high level
OK
OK
1) Inverter cable disconnection.
2) Inverter of LCD module failure.
Trouble Shooting
Is +15V supplied to P803
pin 3, 4 to inverter PWB?
Failure point
NG
Inverter cable disconnection.
Is a "H" level being output in the TTL level from I300 pin 143
NG
Or, is INV_EN signal of the rectangle being output?
Check the PWM signal of the input from I303 pin 7 is a BRI signal
NG
Failure point
NG
Failure point
Printed wire broke between
I300 pin 143 and I307 pin 5
Failure point
1) Printed wire broke between
I303 pin 17 and I307 pin 3
2) I307 failure.
H15AAX (AL502)
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