Samsung PN51D550 Five double blinks

[Muggz]

Hi everyone,

I recently had trouble with a Dell monitor, and you guys really went above and beyond to help me, and I was able to fix it! Thank you!

My TV broke a couple weeks ago, and I want to get it fixed for my wife.
Model: Samsung PN51D550C1FXZA (I often find it online as just PN51D550 or split as PN51D550 C1FXZA).
Specs: 51" 1080p Plasma 3D TV

Symptoms: After plugging it in, it turns on then off then on then off, 4-5 times total, and then the power light does 5 double-blinks. No picture on the display.

Troubleshooting so far:
- I found another thread about this TV, but the picture links are broken.
- I bought a replacement power supply board (model BN44-00444A) from TV Parts Today. I swapped out the board, but the symptoms did not change. It cost about $40-45 shipped. The last picture below is the old board I took out of the TV. Pic 3 is the new board.
- I am a novice to microelectronics, but I do have a multimeter, a hot air soldering station, and a LED blacklight tester (although I've never used it yet). I fix phones and laptops, and this is my first time trying to fix a TV, although I've repaired 3-4 monitors before.

Would anyone please be willing to help me? I will do my best to follow instructions if anyone can walk me through what to do or what to check.

[dick_barton]

Re: Samsung PN51D550 Five double blinks

A good starting point is to give the voltages within the two red boxes.
If you can give the :-
1. Connector name
2. Pin Number, Legend Name, Voltage
Pin Number, Legend Name, Voltage
etc for all the pins

[Muggz]

Re: Samsung PN51D550 Five double blinks

A good starting point is to give the voltages within the two red boxes.

Thank you for responding. What do you mean by "red boxes" please?

[dick_barton]

Re: Samsung PN51D550 Five double blinks

It would have helped you if I had remembered to include the picture. Ooops

[Muggz]

Re: Samsung PN51D550 Five double blinks

Here is a close-up of that corner of the power board. I'm not sure it's the power board though, because replacing it resulted in the same symptoms as before? That said, I will absolutely perform any troubleshooting steps anyone gives me to the best of my ability.

[dick_barton]

Re: Samsung PN51D550 Five double blinks

Check the resistance from VA and VS to chassis and see if there's a short circuit. If there is try and idenrtify which board. They go off to Xmain and Ymain boards. Unlikely to be the power supply if changed.

[Muggz]

Re: Samsung PN51D550 Five double blinks

I am very sorry to disappear for so long. Real life stuff hit me. I was able to successfully test all of the pins going from the power board to the X and Y boards (although I could not tell you which one is the X board and which one is the Y board). All of the voltages are correct on both ends of the connectors. Of course, as it turns on and off 4 to 5 times, I am only able to get the reading for a split second before the TV shuts back off.

Can anybody PLEASE advise the next step to troubleshoot?

[Muggz]

Re: Samsung PN51D550 Five double blinks

Okay, what I tested were the logic boards, not the X and Y boards.

So, I followed this guy's video, and determined the X board is bad.

Does anyone know where I can find the same X board?

It looks like the part number is LJ41-09422A. The one in my TV is R1.3. I found this eBay listing but it was R1.2. I also found this vendor, but it doesn't specify what revision the PCB is.

How critical is it that the replacement board is R1.3?

[Muggz]

Re: Samsung PN51D550 Five double blinks

Replacing the X board fixed it!

[dick_barton]

Re: Samsung PN51D550 Five double blinks

Thanks for the follow up.