Does
the back light
function and then
turn off or is there a
dark horizontal area
on the
screen?
YES
NO
Is
24 VDC
at pins 1 through 5
of P860 and 12VDC at
pins 7 and 8 of CN91
present while
the unit
is on?
YES
NO
Replace the
Power supply
module.
YES
NO
If it is
available , try one or both
inverters. If this does not
help, replace the LCD
display.
***
Backlight
Troubleshooting
Replace the
Main module.
Is 3.3VDC
present at pin 1 of
CN653 shortly (.5 sec)
after the unit is
turned on?
Replace the
display.
***
Remove
AC, and unplug the
LVDS cable(s) as well as
P860, and P861. Do both
voltages return when AC is
reapplied and
the unit is turned
on?
YES
NO
SMART2009-LCD909-V5 Page 6 of 14
