Sanyo FVM3982 Service Manual page 5

Repair Flow Chart:Trouble Condition
Green Power is on,but LCD backlights are not on.
Backlights do not turn on, or only turn on and back off.
Is the 0V supplied from "CN3 Pin10"
Yes:0V
Is the 50V sine wave (RMS) supplied from "CN3 Pin 1/2"
and 50V sine wave (RMS) supplied
Yes:+/-50V sine wave(RMS)
Confirm wire harness connection
between analog board &Power board
and between Power board and panel .
Power LED turns ON,
but LCD backlight is not ON
or only turned ON and then
back OFF.
On analog signal board:
Is the "BL_SW" voltage (5V)
Supplied from "K17 Pin13"?
See TABLE *1.0
Yes:5V
On Power board:
during LED on time?
See TABLE *3.0
On Power board:
" CN3 Pin 4/5"
See TABLE *4.0
Panel is not working
Replace panel.
No:0V
On digital board:
Is 3.3V supplied to"K5A Pin19" ?
See TABLE *2.0
Yes:3.3V
Replace "analog board and
wire harness".
No:over 0.1V
Panel is broken.
Replace "Panel".
No:0V
Power board is not working.
Replace "Power board".
No:0V
Digit board is not working.
Replace "digital board".
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