LG 50PQ30 Training Manual page 39

Using two 100 Watt light bulbs, attach one end to Vs and the other end to ground. Apply AC to SC101. If the light bulbs
turn on and VS is the correct voltage, allow the SMPS to run for several minutes to be sure it will operate under load. If
this test is successful and all other voltages are generated, you can be fairly assured the power supply is OK.
Note: To be 100% sure, you would need to read the current handling capabilities of each power supply listed on the silk
screen on the SMPS and place each supply voltage under the appropriate load.
4 5 8
or or
Gnd
Vs
1 2
Pins or
P811
Check Pins 1 or 2
for Vs voltage
Check Pins 6 or 7
for Va voltage
You can even pre-
align the Vs and Va
voltage to the
panel's label.
But you must
recheck when you
can get a white
raster.
L102
Check Pins 1~4
For M5V
Note: This SMPS will run without a load, however if the Vs is not loaded,
the 17V may pulsate up and down.
It is always best to test the SMPS under a load using the 2 light bulbs.
50PQ30 SMPS STATIC TEST UNDER LOAD
P811
1
STBY 123V
RUN 382V
F801
4A/250V
F801
STBY 160V
RUN 382V
F302
1A/
250V
SC101
T901
VR901
Vs
1,2) 17V
3,4) Gnd
T301
5,6) 12V
7,8) Gnd
9,10,11) +5V
12) Stby 5V
13,14) Gnd
15) n/c
16) Gnd
F101
17) 5V Det
18) AC Det
10A/250V
19) RL_On
20) VS_On
AC In
21) M5_On
22) Auto Gnd
23) Stby 5V
24) Key_On
39 Published November 2009
Provided the Power Button is
closed, any time AC is applied to
the SMPS, STBY 5V and AC DET
should be present.
If AC Det is missing,
the TV will come on then shut
off within 10 Sec.
This will happen each time the
VR502
TV is turned on.
Va
17V turns on
Check Pins 11 or 23 for
with Vs On
command
Check Pin 18 for
IC701
Check Pin 9,10,12 for
Check Pins 1 or 2 for
P813
1 23
Check Pins 5 or 6 for
2
24
P813
5V SBY
AC Det (5V)
(+5V)
17V
12V
50PQ30 Plasma