Abnormal Plug And Play Operation; Abnormal Ddc2 (D-Sub); Abnormal Ddc2 (Dvi) - NEC MultiSync 20WGX2 Series Service Manual

6. Abnormal Plug and Play Operation

6.1 Abnormal DDC2 (D-SUB)

Confirm the output of serial data on I303 pin 5
synchronize SCLK at TTL level.
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 I303 pin 5 and P301 pin 12 may have failed.
4) R311, R314 open.
5) I303 pin 5 has been shorted.
6) Cable failure.
7) Same as I303 pin 6.

6.2 Abnormal DDC2 (DVI)

Confirm the output of serial data on I334 pin 5
synchronize SCLK at TTL level.
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 I334 pin 5 and P304 pin 7 may have failed.
4) R318, R506 open.
5) I334 pin 5 has been shorted.
6) Cable failure.
7) Same as I334 pin 6.
OK
Failure point
OK
Failure point
NG
NG
6 - 8
Failure point
I303 failure.
Failure point
I334 failure.