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
I306 pin 95, 91, 87 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 I306 pin 95.
2) R346 short.
3) C348 open.
4) R345 open.
Is the pulse of the TTL level being
output to P306, P307 from the
data line of I306?
OK
NG
Failure point
1) Printed wire broke between I306 data line and P306, P307.
2) I317 failure.
Check the negative horizontal
sync pulse output to P307 pin 38
from I306 pin 74 at TTL level.
OK
NG
Failure point
1) Printed wire broke between I306 pin 74 and P307 pin 35.
2) R350 open
3) C383 short
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