LG 50PQ30 Training Manual page 90

Control Board Additional Troubleshooting Tips
Control Board Additional Troubleshooting Tips
For quick Control board test. (All connectors Disconnected).
Jump 5V from Power
Supply to IC201 Pin 3.
(Bottom Pin)
If the LED blinks,
Pretty much
guaranteed,
Control Board is OK.
When the Television has a problem related to;
1) Shutdown caused by Main Board.
2) No Video (No Picture) Sound OK.
This can be checked by the following.
(1) Disconnect the Main board from all connectors. Apply AC power.
Since P813 is not connected to the SMPS, the set will come on.
Short the two pins on the Auto Test Pattern lands.
If there is a picture of cycling colors and patters, the Y-SUS, Y-Drive, Z-SUS, Power Supply, Control board,
X-Boards, TCPs and Panel are all OK.
Use the same test for problem (2) above to tell if the No Video is caused by the Main board or failed LVDS cable.
90 November 2009 50PQ30 Plasma
Confirm B+ to Control the
Control Board
VS_DA
3V ~ 3.3V
(Note, this TP can also be
Used as an External Trigger
For scope when locking onto
the Y-Drive signal).
Quick observation
Of LED blinking
Tell if the Control
Board is running.