Trouble Shooting
Page 9
NEC-FA150ATUA
7. Abnormal plug and play operation (
Abnormal DDC2
)
"Read" Confirm the output of serial data on I304 pin 5 SDA at TTL level.
O K
N G
Failure point
I304 failure.
Failure point
1) The host machine isn't communicating in DDC2 mode.
2) The video cable may have failed or may not to have connections for DDC.
3) Between I304 pin 5 and P302 pin 12 or I304 pin 6 and P302 pin 15 may
have failed.
4) FB307, R323, FB308, R324 open.
5) Cable failure.
"Write" Confirm the Q308 are On and I304 pin 7 at low level.
O K
N G
Failure point
1) The host machine isn't communicating in DDC2 mode.
2) The video cable may have failed or may not to have connections for DDC.
3) Between I304 pin 5 and P302 pin 12 or I304 pin 6 and P302 pin 15 may
have failed.
4) FB307, R323, FB308, R324 open.
5) Cable failure.
Failure point
I306 failure.
Check I306 pin 51 at High level
O K
N G
Failure point
Q308 failure.