Acer P223 Service Manual page 27

ACER P223W
26
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5.6 Abnormal OSM display adjust problem
Check the input TTL level whether was changed
when pressed function keys on the P306 pin 4, 5
(normal is high level, when push buttom, generated
Failure Point
I305 is failure.
5. Troubleshooting (continued)
low level plus)
OK
Check the input TTL level of I305
pin89, 90 whether was changed
when pressed function keys.
(Refer to Table 1)
NG
OK
Failure Point
NG
1) Function key wire disconnection.
2) Function key wire is failure.
3) Function key board is failure.
Failure Point
1) Printed wire broke among P306 pin4, pin5; R369 and I305
pin90.
2) Printed wire broke among P306 pin5,R372, and I305 pin89.
3)C386,C388 ,C389,C390 are short.