LG 42PQ30 Training Manual page 40

Using two 100 Watt light bulbs, attach on end to Vs and the other end to ground. Apply
AC to SC101. If the light bulbs turn on, allow the the SMPS to run for several minutes to
be sure it will operate under load. If this test is suscessful and all other voltages are
4 5 8
or or generated, you can be assured the power supply is OK.
Gnd
P811
1
1 2
or
Vs
Also check
Pins 6 or 7 for
proper Va
Note: The light bulb test is not necessary for the SMPS to turn on and stay on.
This SMPS will run without a load. But it is necessary to test the SMPS under a load.
42PQ30 SMPS (LIGHT BULB) STATIC TEST UNDER LOAD
42PQ30 SMPS (LIGHT BULB) STATIC TEST UNDER LOAD
Both F801
and F302
read from
Hot Gnd
F801
4A/250V
Stby 338V
Run 388V
F302
1A/250V
Stby 338V
Run 388V
8A/250V
SC101
T901
VR901
Vs
T30
1
AC In
40
The Main PWB will
not function without
STBY 5V and AC Det
arriving from the
Check Pins 9, 10, 11
or 12 for 5V-STBY
VR502
Check Pin 18 for
Va AC Det 5V
Any time AC is
applied to the
SMPS, STBY 5V
and AC DET should
be present.
IC701
Check Pins 1 or 2
P813
1 23
Check Pins 5 or 6
2
24
SMPS.
for 17V
for 12V