July 2009 LCD DV
42LH40
28
Continue if the 1
st
test was OK. Leave original resistor in place.
(3) Add another 100
Ω
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.
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 Backlights.
DO NOT check these when AC is applied as they carry 1.2Kv each.
Note, either of the connections are unplugged, the backlights will not
light.
TEST 2 Power Supply PWB Backlights Test
TEST 2 Power Supply PWB Backlights Test
P700 Connector disconnected from the Main PWB. Apply AC after adding jumper.
Use P700
Side to insert
resistors
