Samsung 50" Plasma relay clicks, nothing else

[Snype32]

I have a Samsung pn50c540g3f 50" plasma. When plugged in, the red power light comes on. when touched, the tv clicks a few times, and goes back to the red light. Screen does not come on. I looked around on the net a bit and it looks like it could be bad caps, or the buffer board. Just wondering if anybody here is familiar with this, and where I should start. Thanks!

[ReeceyBurger123]

Re: Samsung 50" Plasma relay clicks, nothing else

Good god, how we supposed to guess ? Take the back off and get diagnosing it lol ? No point just throwing random ideas in there you need to find out what you need to add to a thread and what to test which there are plenty of things on here to help.

[Snype32]

Re: Samsung 50" Plasma relay clicks, nothing else

Sorry I should have clarified, I have taken the back off, all caps appear fine. It seems like from what I have found, there are usually two culprits, bad buffer boards, and power supply/bad caps. I was mostly wondering if people here were familiar enough with these to say which was more likely. If bad buffers are a strong possibility, I thought I would save everybody some time because I don't have the facilities to fix that. Bad caps are no problem for me to fix. I'll be doing some VA and VS checks shortly.

[ReeceyBurger123]

Re: Samsung 50" Plasma relay clicks, nothing else

On this chassis check for shorts from Vs to ground on the Ysus and Xsus the buffers are normally very reliable in this chassis sus boards are not and usually short causing Psu to current limit and click over and over.

[Snype32]

Re: Samsung 50" Plasma relay clicks, nothing else

Ok...so I've done a few tests. First to clarify, when first powered on, there are 2 back to back clicks, short pause then the third click. It will repeat that every time the power button is clicked. It happens fairly quick, so hard to get an accurate reading. Next I disconnected the cable going from the main power supply to the second board in my pics. Is that the Xsys or Ysus board? anyway, with that disconnected, I tested VA and VS on the main power supply. They momentarily read their specified voltages and then drop off. The tv also sings its little samsung song. I tested for shorts on what I assume is either the Ysus or Xsus, and sure enough, there is very little resistance from ground to VS. Not quite a dead short, but very close. So I'm guessing some component is shorted on that board.

Thanks for the help so far.

[Snype32]

Re: Samsung 50" Plasma relay clicks, nothing else

Looked up the board, it's the ysus

[ReeceyBurger123]

Re: Samsung 50" Plasma relay clicks, nothing else

Ok sounds like the Ysus then, could possibly be that the Xsus is damaged too when the Ysus blew as these use chained ERC (energy recovery) meaning if the Y blows it can kill the X basically. Does your meter have diode mode easier to test ?

[Snype32]

Re: Samsung 50" Plasma relay clicks, nothing else

Yes I have a meter with that function. What area should I start testing? There looks to be a couple rows of what look like mosfets. I was thinking of starting there unless there is a more likely place to go.

[ReeceyBurger123]

Re: Samsung 50" Plasma relay clicks, nothing else

Start testing the devices mounted on a heatsink but mainly if Vs is shorted to ground to diagnose the bad susboard.

[Snype32]

Re: Samsung 50" Plasma relay clicks, nothing else

So I think I found the culprit. a RJP30E2 transistor. Shorted in every direction. I was told that this would be a replacement:

https://www.digikey.com/product-sear...DPK-00%23T0-ND

Higher wattage, voltage, and current rating. I also found a small burnt trace and an assuming that it happened because of the shorted part. Should I check anything else out or hope that this is it?

[Snype32]

Re: Samsung 50" Plasma relay clicks, nothing else

I just removed and tested a rd2006 rectifier as well. It appears to be shorted as well? how are these tested?

Thanks!

[ReeceyBurger123]

Re: Samsung 50" Plasma relay clicks, nothing else

Same as a transistor, you should have a voltage drop in one direction and not in the other. Also the diodes rarely rarely fail on sustain electronics. There might be other transistors shorted so keep checking the circuit before removing the diode.

[Snype32]

Re: Samsung 50" Plasma relay clicks, nothing else

The RD2006 is defiantly shorted in both directions. I will be double checking the other components as well.

Thanks for the help so far.

[ReeceyBurger123]

Re: Samsung 50" Plasma relay clicks, nothing else

Ok best to check everything let me know