Abnormal Screen - LiteOn B17AAU Service Manual

4. Abnormal screen

Check the R, G, B video signal from computer input on
D-Sub R, G, B connector.
O K
Check the R, G, B input signals on I315 pin E1, D2, C1
respectively that their level is 0.7Vp-p maximum.
O K
Is the pulse of the TTL level being output to I319, I320
from the data line of I315?
O K
Check the negative horizontal sync pulse output to
RN314 pin 8 from I315 pin F20 at TTL level.
O K
Check the negative vertical sync pulse output to RN314
pin 7 from I315 pin F19 at TTL level.
O K
Check the positive DE pulse output to RN314 pin 6 from
I315 pin F18 at TTL level.
O K
Check the SHFCLK OUTPUT to L322 pin 2 from I315 pin
G20 at TTL level.
O K
Page 6
N G 1) No R, G and B video signal output from host computer. Check
2) Video signal cable disconnection.
In the case of the Red signal. (A Green and Blue signal is the same
N G
path, too.)
1) Printed wire broke between D-Sub(R) and I315 pin E1.
2) R339 short.
3) C359 open.
4) R337 open.
N G
1) Printed wire broke between I315 data line and I319, I320.
2) I315 failure.
N G
1) Printed wire broke between I315 pin F20 and RN314 pin 8.
2) I315 failure
N G
1) Printed wire broke between I315 pin 73 and RN314 pin 7.
2) I315 failure
N G
1) Printed wire broke between I315 pin F18 and RN314 pin 6.
2) I315 failure
1) Printed wire broke between I315 pin G20 and L322 pin 2.
N G
2) L321 open
3) C583 short
4) C590 short
5) L322 short
6) I315 failure
Next Page
B17AAU / B17ANU / B17AAY
Failure point
computer
Failure point
Failure point
Failure point
Failure point
Failure point
Failure point
Trouble Shooting