NEC AccuSync LCD71VM - Abnormal Screen

6-6
4. Abnormal Screen
NG
NG
OK
OK
Check the R, G, B video signal from compute
r
input on D-Sub R,G,B connector.
Failure point
1) No R, G and B video signal output from hos
t
computer. Check computer.
2) Video signal cable disconnection.
Check the R,B,G input signals on U405 pins
135, 131, 127,respectively that their level is
0.7Vp-p typical.
Failure point
Printed wire broke between D-Sub(R,G,B) and
U405 pins 135,131,127.
Proceed section 7 “Checking the scaling IC movement”.