Acer A221HQV Service Manual page 40

ACER A211H/A221HQ
38
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5.2.4 Abnormal screen
5.2.4.1 Abnormal screen for VGA source
Check the R, G, B video
signal from computer input on CN302
of video connector.
Check the R, G, B input
video signals on I310 pin 25, 27, 30
respectively that their level is 0.5 to 1.0
Check the H, V SYNC input signals on
I310 pin 21, 22 respectively that signal
Check all LVDS signals being output
to CN306 from I310?
Proceed "Checking the resolution change IC
movement" section.
5. Troubleshooting (continued)
OK
Vp-p.
OK
and level.
OK
OK
Failure Point
NG 1) No R, G, B video signals output from
host computer, check computer.
2) VGA video signal cable disconnection.
Failure Point
In the case of the Red signal. (Green and Blue
signal is the same path, too.)
1) Printed wire broke between CN302 pin 1 and
NG
I310 pin 30.
2) Video cable is failure.
3) L303, R313, R314 are open.
4) R315 is short.
5) C316, C318 is short or open.
Failure Point
1) Printed wire broke between I306 and P302.
NG 2) L306, R327, R328 are open.
3) R329, R330 if is 2.2K ohm.
4) D305, D306, C330, C331 are short.
5) Video cable is failure.
Failure Point
NG
1) Printed wire broke between I310 and CN306.
2) LVDS wire failure.