Repair Flow Chart:Trouble Condition
Green Power is on, but LCD backlight is not on.
Backlight does not turn on, or only turns on and then off.
Power LED turns ON,
but LCD backlight is not ON
or only turns ON and then
OFF.
For analog signal board:
Is the “BL_SW” voltage (3.3V)
Supplied from “K8B Pin13”?
For Power board:
Is the 0V supplied from “CN3 Pin10”
during LED on?
Panel is broken.
Replace “Panel”.
On digital board:
Is 3.3V supplied to”K5A Pin24” ?
Digit board can not work.
Replace “digital board”.
For Power board:
Is the +20 sine wave in
“
CN3 Pin 1/2/3”
and -20 sine wave in
“
CN3
“ Pin 4/5/6”?
Power board can not work.
Replace “Power board”.
Confirm wire harness connection
between analog board &Power board
or between Power board and panel .
Panel can not work.
Replace panel.
Replace “analog board and
wire harness”.
No:0V
No:0V
Yes:3.3V
Yes:3.3V
Yes:0V
No:over 0.1V
No:0V
Yes:+/-20 sine wave(RMS)
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