Checking The Back Light Unit - NEC MultiSync 20WGX2 Series Service Manual

3. Checking the Back Light Unit

Check the BKLT_EN signal of the
rectangle input P303 pin 13 at TTL high
level
OK
Check the PWM signal of the input from
I308 pin 202 is a PWM signal.
OK
Failure point
Inverter of LCD module failure
Is a "H" level being output in the TTL level
NG from I308 pin 59
Or, is BKLT_EN signal of the rectangle
being output?
OK
Failure point
NG
1) Printed wire broke between
I308 pin 202 and P303.
2) I312 failure.
6 - 5
Failure point
NG
Printed wire broke between I308
pin 59 and P303.