Acer A221HQV Service Manual page 39

5.2.3 Checking the back light unit:
Is +22V supplied to inverter PWB?
(by the power board)
Check the BACKLIGHT_ADJ
signal of the CN301 pin 13 from I310
pin 114 is a PWM signal.
Failure Point
Back light unit of LCD module is failure.
5. Troubleshooting (continued)
NG
OK
NG
OK
Failure Point
1) The wire between Power +22V and
Inverter +22V is broken.
2) Power board failure.
Failure Point
1) Printed wire broke between CN301
pin 13, and I310 pin 114.
2) R301 is open.
3) I310 is failure.
ACER A211H/A221HQ 37
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