Sanyo P50842-00 Troubleshooting Manual page 5

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.
Yes:0V
Is the +20 sine wave in
and -20 sine wave in
Yes:+/-20 sine wave(RMS)
Confirm wire harness connection
between analog board &Power board
or between Power board and panel .
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"?
Yes:3.3V
For Power board:
Is the 0V supplied from "CN3 Pin10"
during LED on?
For Power board:
CN3 Pin 1/2/3" "
CN3 " Pin 4/5/6"?
"
Panel can not work.
Replace panel.
No:0V
On digital board:
Is 3.3V supplied to"K5A Pin24" ?
Yes:3.3V
Replace "analog board and
wire harness".
No:over 0.1V
Panel is broken.
Replace "Panel".
No:0V
Power board can not work.
Replace "Power board".
No:0V
Digit board can not work.
Replace "digital board".
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