LG 50PG20 not turning on, is power board EAY41360901 bad?

Question: 
I have in my workshop this tv  LG 50PG20 no turn on  when you hit the power botton only makes just clicks up front and LED changes from red to blue and back to red with another click I measure the voltages on vs, va, 15v, 12v 5v everyone is present only momentarily.  YSUS checked and not short, I also checked with ZSUS and neither is shorted 

Answer: 
While I can't tell you what is wrong with the TV I can probably tell you how to fairly quickly isolate the power board as a potential suspect.

There are two different power boards for LG 50PG20 that I am aware of and they are both compatible and suitable for this test.

The more popular is EAY41360901.

All you need to verify essential functionality of the board is disconnect all cables from it except from the main AC power cable.

To do that safely, first disconnect the TV from the AC outlet, let it stay 5-10 minutes so that the large capacitors on the power board discharge to low enough voltage.

Then you can disconnect all cables on the signal connectors on the board leaving only the main AC cable connected.

You may take the board out or leave it in the TV, whatever you prefer.

Then you simply connect it to AC power.

The board should click once and should stay on until you disconnect it from AC power at which point it should click again signalling deactivation.

While activated (connected to power) you should be able to measure Vs and Va voltages. 

I do not remember their exact values, but they are something like 207V and 67V. Again, those values may not be exact...I think the exact ones can be found on the board itself.

If you get Vs and Va stable then the problem is most likely not in the power board.

A more complete test can be done by loading the board by connecting two 100W bulbs in series to the Vs, but in my experience that's actually not necessary 99% of the time.

If the board still shuts itself off then you should look for service or replacement.

Here are a few things that may help you replace or repair your EAY41360901:

http://www.coppelltvrepair.com/search?Q=EAY41360901&As=false&Pf=&Pt=&Sid=false&btnsearch=Search

Hope this helps!