NEC MultiSync 20WGX2 Service Manual page 97

4. Abnormal Screen 4. Abnormal Screen
Che ck the R Che ck the R , G, B video signal
computer input on D-Su computer input
Ch eck the R, G, B input si Ch eck the R, G, B input signals on I308
pin 139, 142 , 144 respectively that thei pin 139, 142
level is 0. level
Che Che ck all ck all LVD LVD S signal pins,
Process "8. Checking the resolution change IC Process "8. Checking the resolution change IC
movement" section. movement" section.
, G, B video signal from from
on D-Su b R, G, B b R, G, B
connector. connector.
O O K K
gnals on I308
, 144 respectively that their r
is 0.7Vp-p m 7Vp-p m aximum aximum . .
O O K K
S signal pins, output from output from
I308, I311, I312. I308, I311, I312.
O O K K
Failure point Failure point
N N G G
1) No R, G and B video signal output f 1) No R, G a nd B video signal output from
host computer. host computer. Check com
2) Video signal cable disconnection. 2) Video signal cable disconnection.
Failure point Failure point
In t In the case of the Red signal. he case of the Red signal. (A Green a
N N G G
Blue signal is the same path, too.) Blue signal is the same path, too.)
1) Printed wire broke bet 1) Print ed wire broke between D
I308 I308pin 128 pin 128, 129. , 129.
Failure point Failure point
N N G G
1) I308 , I311, I312 1) I308 , I311, I312failure.
2) Printed wire broken between I30 2) Printed wire broken between I30 8 8 and
I311, I321. I311, I321.
3) Printed wire broken betwe 3) Printed wir e broken betwe en I311, I312
and P305. and P305.
6 - 6 6 - 6
rom
Check com puter puter
(A Green and nd
ween D -Sub(R) and -Sub(R) and
failure.
and
en I311, I312