BenQ G2420HD, Product Service Manual

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5.6. Trouble Shooting Guide
5.6.1 No Display or display is unstable on analog, digital or video port:
No picture or picture unstable on
Analog port or DVI port or HDMI
port
Power off
Does cable plugs in connector?
Is 5V from power
board normal ?
Turn on power
Y
N
Plug the cable then turn
on power again.
Check Power BD 5V
output
Y
N
N
Y
Is Power LED light Green or
amber?
Check Key BD and Key
BD cable
N
Y
Is Power LED status normal?
Replace Power Key BD
N
Check crystal CKT or
replace it (Y1)
N
Replace interface BD
N
Does crystal work correctly?
Is interface BD normally?
Replace panel
Y
Y
Y
Is LVDS cable connect OK?
Plug LVDS cable again
or replace it
N
Y