Samsung PN50A550 / PN58A550 Owners Thread - Page 188

Just one question, does anybody know if the letter designation at the end of the main board part number (A thru E) makes a difference? I need a "B" but can only find an "E". Thanks

I can say that it didn't make a difference in my case-- I supposedly needed a "B" but ordered a "D", installed it, and it works. It also looks exactly the same. And every potential supplier listed them as compatible, interchangeable parts when I was searching for one. I think you're safe. Good luck!

Finally replaced the mainboard. Found one at PartStore.com which is apparently owned by Best Buy. It was approx $100 shipped got it in 3 days . Simple process of removing back panel then disconnecting the cables to the board and swapping the boards out. Powers up like new now. Thanks for all the posts about this and will probably never buy a Samsung product again.

Can anyone confirm the part number for the PN58A550 main board?

Thanks

No one?

Hey guys!

I have a PN58A550 and after 4 years of ownership, I am now having the cold start up issue where it turns on and off along with severe static noise at times and bad picture. It's now to the point where I have to leave the TV on for almost 20-30 minutes before I can get a good solid picture. I am now thinking if I should call a service technician or just get rid of it and buy another HDTV. Here are some youtube videos of my issues and is this due to a bad power circuit board?

Part 1 - first initial startup in the morning. It just turns on and off.
http://www.youtube.com/watch?v=E3OUvCuA_fk

Part 2 - Screen then turns pink after 5 minutes then shuts off and turns on again.
http://www.youtube.com/watch?v=P0lxWVlPy7c

Part 4 - few minutes later I get flashing blue things then turns off and on.
http://www.youtube.com/watch?v=kcsIplJW0CY

Part 5 - pink/purple screen and again it turns on and off.
http://www.youtube.com/watch?v=cBuy8H6ZPLw

Part 6 - after leaving the TV on for more than 20 minutes, I get the Samsung screen saver. I turn on the receiver and I get the noise and bad picture and its turns off and on.
http://www.youtube.com/watch?v=IoJFoUeKWJM

Part 7 - Bad picture and bad noise that lasts for a couple of minutes, turns off then on, and everything is ok.
http://www.youtube.com/watch?v=uWt9_nSMgzs

I had the exact same issue and I was able to fix my tv without replacing any boards!

It could be due to power board or the main board. For me, it was the main board because the voltages that the power supply board was outputting to other boards were correct (as marked on the board itself). I singled out the problem to be with the mainboard. You can either replace the mainboard but before you swap the main board you can try fixing it by reflowing it. There are tutorials on youtube on how to reflow hp laptop motherboard. You can use the same procedure. I fixed my main board (BN94-01658A) by heating it in the kitchen oven for 8 mins at 200degree C and allowed it to naturally cool.

If your main board is fine but the power supply board is bad (voltages its outputting are not within the marked values; you can use a DC multimeter to test ) you should be able to visually inspect and replace all the bad capacitors on the power supply board.

Hope it helps everyone that is having startup/clicking issues
Edited by Ibadat - 12/5/12 at 12:26am

Thanks! Unfortunately I replaced the power supply board and still had the same issue. I'll look into the main board next. Thanks again!

Ive had my PN50A510 (550's little brother) for about 4.5years now. Still running strong with no signs of quitting. Although she has lost her luster over the years (still looks great though) and image retention is a bit annoying (goes away after a minute or two). For the $1100 I paid back then it has exceeded my expecatations up to this point. I'm surprised people are still fixing these sets, I would have assumed they were considered dinosaurs by now.

I had planned to go panasonic after this TV quits on me but brand loyalty may sway me on this one given the performance and reliability of my current sammy.

Ibadat,

Thank you again for your information. I bought a main board but turned out to be the wrong part number. I was frustrated at this point and figured I put the old main board in the oven (400F for 8 minutes) and see what happens. If it doesn't, then it would be a good reason to get another new HDTV. After I pulled it out of the oven, there were 4 small soldering balls on the tray and I thought crap I broke it. I installed it anyways and BAM, TV started up fine with a clear picture.

Now I have to return or sell this main board that I don't need.

Jon C.

How to remove dust between the protective glass and the screen?
I assume, that the protective glass is glued to the front bezel and the task is to remove the plasma screen without breaking it.
Is it difficult to disassembly the TV?
Any tips, recommendations ?

Here is a picture of the dust in the two lower corners:

UPDATE:

The reflow technique only lasted for a week. Bought a reman. main board and everything is working fine now. I bought the main board from TVServiceParts.com. Here's the link
http://www.tvserviceparts.com/BN94-01660B.html

Anyone have blink codes for this TV?

Mine has failed with no picture but it powers on and has sound.

Power light is on in standby and after powering on it flashes once quickly, then a long pause, then 4 more flashes.

I have searched the net and found either that Samsung doesn't use blink codes (?) or that they do but no one says what they are.

I had the same problem that several people have mentioned...upon power up, funny colors over screen and screeching noise...after a couple of cycles it finally comes on and works. My problem was the main board. Rather than put the whole board in the oven (lots of plastic on this board that should not go in the oven) I made a mask from aluminum foil that just revealed the chip with the heat sink on it. Removed the heat sink. Using a multimeter with a temperature probe, I secured the thermocouple(temp probe) on top of the chip to monitor its temperature. Using a heat gun, I brought the surface of the chip(evenly) up to 200 deg C for 90 seconds, then brought it between 220 and 240 for another 90 seconds, then brought it up to 260 deg C +/- 5 deg C for 30 seconds, then slowly let the temp come back to room temperature. After cooling and re-installing the board (I also replaced the heat sink with a larger one), it has powered up perfectly for the last month. I also found 1 capacitor going bad on the "Y" board and replaced it. It wasn't completely bad yet, but it only measured 1/3 of its rated value. I found the procedure in another forum for fixing a video chip on a laptop. It's much better than heating up the whole board.