![HP F1523 - Pavilion - 15](http://html.mh-extra.com/html/hp/f1523-pavilion-15-lcd-monitor/f1523-pavilion-15-lcd-monitor_service-manual_159601021.webp)
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vf15 / FP15 / f1523 / FP5315
6. Abnormal plug and play operation
Confirm the input of serial clock on I308 pin 6 SCL at TTL level.
NG
OK
Failure point
I308 failure.
Failure point
1) The video cable may have failed or may not to have connections for DDC.
2) Between I308 pin 6 and P305 pin 12 may have failed.
3) R405, R323 open.
4) Cable failure.
Confirm the input of serial data on I308 pin 5 SDA at TTL level.
NG
OK
Failure point
I308 failure.
Failure point
1) The host machine isn't communicating in DDC mode.
2) The video cable may have failed or may not to have connections for DDC.
3) Between I305 pin 5 and P305 pin 11 may have failed.
4) R406, R324 open.
5) Cable failure.