LG 42PJ350 Training Manual page 40

42PJ350 Power Supply Static Test with Light Bulb Load
42PJ350 Power Supply Static Test with Light Bulb Load
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.
Pins 1 or 2
VS
Gnd
Pins
4 or 5 or
P811
Check Pins 1 or 2
for Vs voltage
Check Pins 6 or 7
for Va voltage
Note:
To turn on the Power Supply;
1) With Main Board connected, press power.
2) Without Main Board connected SMPS will turn on automatically.
Any time AC is applied to the SMPS, STBY 5V will be 3.49V and will
be 5.23V when the set turns on.
AC DET WILL NOT be present until set comes on.
If AC Det is missing, the TV will come on and shut off in 10 Seconds.
F801
4A 250V
8
L601
L602
VR901
T901 VS Adj
F302 2.5A
250V
T301
F101
10A 250V
SC101
AC In
Check Pins 13 or 14
For 5V SBY (5.23V)
Check Pin 8
For Error Det (4.9V)
Check Pin 16
For AC Det (4.45V)
40
VR502
VA Adj
Note:
Always test the SMPS under a
load using the 2 light bulbs.
Abnormal operational
conditions may result if not
loaded.
P813
P813
Check Pins 1 or 2
For 16.79V
Check Pin 5,6 and 7
For (+5V) 5.24V
August 2010 42PJ350 Plasma