AOC M19W531, Service Manual

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19" LCD Color Monitor AOC M19W531
40
7.2 Trouble Shooting
7.2.1 Main Board
No Display on Screen
NG
Power has some issue. Check
Correspondent component.
Is there any shortage or cold solder?
OK
White
NG
Red or no
displays
Connected the Signal
cable again, and
check LED status.
Blinking
Disconnected the Signal
cable (Loose the Signal
cable), is the screen show
“no signal”?
Connected the
Signal cable again,
check LED status.
OK
NG
Measured CN101 pin5, 6= 12V?
Measured CN101 pin 9, 10 =5V?
U404 pin 4/17= 2.5V
，
pin
86/100=3.3?
It will
be OK
Check Power switch
is in Power-on
status, and check if
Power switch had
been stuck?
Green
OK, Keyboard no stuck
OK
Check the LVDS Harness from CN115
NG
OK, Wire tight enough
Check
Panel-Power Circuit
Block
OK, Panel Power OK
Replace
Power board
and Check
Inverter
control relative circuit
Re-do White balance adjust
Measured Crystal X104, X102
OK
OK
Replace
U401 (MST51512)
OK, U401 data OK
Check U401
Data-output Block
Measured H/V Input
RGB, (CN102 pin 8,28,
was there have signal?)
Check
Correspondent
component
short/open
(Protection
Diode)