6-7
4. Abnormal Screen
Check the R, G, B video signal from
computer input on D-Sub R, G, B
connector.
OK
NG
Failure point
1) No R, G and B video signal output from host computer.
Check computer
2) Video signal cable disconnection.
Check the R, G, B input signals on
I315 pins E1, D2, C1 respectively that
their level is 0.7Vp-p maximum.
OK
NG
Failure point
In the case of the Red signal. (A Green and Blue signal is
the same path, too.)
1) Printed wire broke between D-Sub(R) and I315 pin E1.
2) R339 short.
3) C359 open.
4) R337 open.
Is the pulse of the TTL level being
output to I319, I320 from the data
line of I315?
OK
NG
Failure point
1) Printed wire broke between I315 data line and I319, I320.
2) I315 failure.
Check the negative horizontal
sync pulse output to RN314 pin 8
from I315 pin F20 at TTL level.
OK
NG
Failure point
1) Printed wire broke between I315 pin F20 and RN314 pin 8.
2) I315 failure.
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