LG 50PG20 Training Manual page 90

Control PWB Quick Check
Control PWB Quick Check
For quick PWB test.
(All PWB connectors
Disconnected).
Jump 5V from Power
Supply to IC121 Pin 1.
If the Temp LED lights,
Pretty much guaranteed, PWB is OK.
But check FL111 and FL112 to be sure they are OK.
When the Television has a problem related to;
1) Shutdown caused by Main PWB
2) No Picture
This can be checked by the following.
(1) Disconnect the Main PWB from all connectors. Apply AC power.
Since P803 is not connected, the set will come on. Short the two pins on the Auto Test
Pattern lands.
If there is a picture of cycling colors, the Y-SUS, Y-Drive, Z-SUS, Power Supply,
Control PWBs and Panel are all OK.
Same test for (2) to tell if the No Video is caused by the Main PWB.
If testing the Z-SUS for functionality
when the Y-SUS isn't running.
Tap the 16V from pin 1 or 2 of
P701 or P803 (removed from
Main PWB) and jump to pin 12 of
P163. Jump 5 V to 5V in on
Control PWB. Confirm a good
waveform output from Z-SUS.
Plasma Spring 2009
90
50PG20