Remove Ac Power - LG 42LH90 Manual

Power Supply Board Backlights Test 2
Power Supply Board Backlights Test 2
P700 Connector disconnected from the Main Board. Apply AC after adding jumper.
Continue if the 1
(3) Add another 100Ω resistor between (5V) pin 7, 8, 9 or 10 and
Pin 20 (INV On).
(4) Apply AC Power. Simulating a Power and Backlight On command.
Backlights Normal:
a) If normal, the backlights should turn on. SMPS OK, Inverter OK.
Backlights Abnormal:
a) Recheck all connections.
b) Confirm the INV On/Off line pulling up to at least 3V.

REMOVE AC POWER:

c) Check the connections to the Inverter.
If the 24V was arriving at the Inverter in Test 1 (pins 1~5 of P203) and
the Inverter On command (INV-ON pin 12 of P203) is arriving, then see
Inverter Section for further testing.
st
test was OK. Leave original resistor in place.
37 February 2010
Use P700
Side to insert
resistors
LCD DV 42LH90