NEC AccuSync LCD71VM - Abnormal Plug and Play Operation

6-7
5. Abnormal Plug and Play Operation
Abnormal DDC2B
Confirm clock and serial data on U401 pins 5, 6.
NG
Failure point
U401 failure.
Failure point
1) The host machine isn't communicating in DDC2B mode.
2) The video cable may have failed or may not to have
connections for DDC.
3) Between U401 pins 5,6 and P401 pins 12,15 may have
failed.
4) Cable failure.
OK