Samsung S5053 Repair

[MaxAsh]

Hello All - just picked up a Samsung 50" plasma free off CL. Owner said it "stopped working during the recent storms" so I'm guessing lightning strike, but who knows. I've repaired multiple LCD screens of various sizes, usually just some capacitor, resistor and/or transitor replacements. Plasma is new to me, and looks a little tougher.

I plugged it in, and immediately the front status light came on blinking blue, and I heard the standard "boot" sound/jingle as if the TV was coming on. This seemed to be a positive sign. Then after about 10 seconds I heard electrical discharge sounds, zapping sounds, and quickly unplugged it. Before I did, I saw a bright flash from the back. Bad, of course. None of these symptoms were mentioned by the original owner, only that it "stopped working".

I popped open the case, and checked the area I saw the flash first. From the back, it was the upper-left area. I took a look at the Y-Main, and as you can see from the image, the components there were completely obliterated. I can't even tell what was there. Reviewing the service manual now and starting my testing.

Can anyone provide some general direction? Based on what got fried so far in the image, am I already in too deep to bother trying to repair at a low cost? Off to do some testing - advice is welcome, thanks!

[MaxAsh]

Re: Samsung S5053 Repair

Update: Just finished testing the power board, everything looks good there. Fuses good, output on Va and Vs are within spec (65 and 198 respectively). I disconnected the output from the power board to the Y and X mains, left everything else connected. TV seems fine as long as X and X Mains are not connected to power.

I tested the components on the X-Main, everything looks good there so far.

On the Y-Main, the top and bottom half of the board are basically mirror images when it comes to several components. The "burned out" section contained 5 diodes (4 zener). Attached is an image from the lower part of the board showing the same components that got damaged on the upper half.

I checked the resistors, transistors, and other components out of circuit, nothing else appears to be damaged from what I can tell. The damage to the fried section might prevent me from replacing components (need to check the back side still). If so, perhaps just a new Y-Main is needed?

Thoughts on the next step?

[MaxAsh]

Re: Samsung S5053 Repair

Update #2 - I hooked up everything except for the Y-Main (and Y-buffer of course). I turned on the TV and everything tests good that's hooked up. I proceeded to plug in an audio/video source and immediately heard the sound coming from the TV speakers. So, aside from the damaged Y-Main diode section, I believe the TV seems to be functioning.

I cleaned up the damaged area on the Y-Main, and unfortunately the frying of the diode section also melted some of the board plastic. There is a larger section of exposed copper and trace damage in the diode area. I could probably try to rig up some components in their proper sequence, but it would be a messy setup. I'm considering a replacement Y-Main (just under $100 including shipping is the best I've found for my board LJ41-04516A). I just want to make sure that there's nothing else I might be missing that may have caused the problem? I don't want to spend the money on a new Y-Main, then find out the problem that blew it is elsewhere. Thoughts?

[Shinju]

Re: Samsung S5053 Repair

I hope you cleaned all that soot off and sanded down to clear off charred section of the board as that will cause arcing.

[MaxAsh]

Re: Samsung S5053 Repair

I hope you cleaned all that soot off and sanded down to clear off charred section of the board as that will cause arcing.

I haven't hooked up the damaged board, I've kept it off the system so no worries there. I've left that board (and the corresponding Y-Buffer) out of the process. With it not hooked up, and everything else connected per usual, the TV appears to work fine (audio/controls/status lights/etc) and simply has no picture. From what I've read, without the Y-Main/Buffer hooked up, you get no picture. Since everything else runs fine, no fuses blow, no other issues, I'm fairly certain the only problem is the damaged board and components. Looking for some confirmation from the more experienced users here, as this is my first plasma repair.

[Hamie]

Re: Samsung S5053 Repair

Have you checked the buffer IC chips for shorts?

[MaxAsh]

Re: Samsung S5053 Repair

Have you checked the buffer IC chips for shorts?

No, only the components on the X and Y Mains, the logic and power boards. I didn't touch the buffer boards, but if it's possible an IC chip short on a buffer could cause this diode frying, I'll test those next.

Am I right in assuming I should grab a whole new Y-main board based on the damage in the pics?

[martino]

Re: Samsung S5053 Repair

There are 5 diodes that went up in flames,not just one..If you look at the pic in this link,you can hover with your mouse over the pic to enlarge it...
http://www.shopjimmy.com/philips-996...main-board.htm

[MaxAsh]

Re: Samsung S5053 Repair

There are 5 diodes that went up in flames,not just one..If you look at the pic in this link,you can hover with your mouse over the pic to enlarge it...
http://www.shopjimmy.com/philips-996...main-board.htm

Correct, I mentioned that in one of the previous posts, but forgot to pluralize it in my most recent one, sorry for the confusion. The "'burned out" section contained 5 diodes (4 zener).

[Hamie]

Re: Samsung S5053 Repair

With the x-main connected and y disconnected you should still get sound.
If you do then the x is good. If you don't, it needs replaced.

Were there any shorts in the buffer?

[MaxAsh]

Re: Samsung S5053 Repair

With the x-main connected and y disconnected you should still get sound.
If you do then the x is good. If you don't, it needs replaced.

Were there any shorts in the buffer?

With X-Main connected and Y-Main disconnected I do get sound. So X is good as you said.

I just checked, no shorts on the Y-Buffer, we're good there.

[tom66]

Re: Samsung S5053 Repair

Do a full test on the Y-buffer:
https://www.youtube.com/watch?v=51SZ...Y&noredirect=1

[MaxAsh]

Re: Samsung S5053 Repair

Do a full test on the Y-buffer:
https://www.youtube.com/watch?v=51SZ...Y&noredirect=1

I performed the tests shown in this video (because it's pretty much the exact same buffer from what I can tell... looks the same, also 50" samsung plasma):
http://www.youtube.com/watch?v=WB238KaaHVA

No shorts found using that tutorial, which is basically the same method as the one you linked, only on a board more closely resembling mine. Double-check me if you want to peek at the video I used, but I think I'm good. If not, please let me know.

[MaxAsh]

Re: Samsung S5053 Repair

I went ahead and re-tested everything last night to be sure. Only thing I can find is the Y-Main issue, so I went ahead and ordered a new board. The damage to the original just looks brutal and trying to rig up something to work around it would have been tricky for me. Plus the components + shipping would have ended up close to half the price of a whole new board, so I went with the latter option. Should be here in a couple days, I'll report back when I try it out.

If anyone goes through this thread and thinks of something I may have missed, or that might blow out the new board because I forgot to check it, please let me know! Thanks

[Hamie]

Re: Samsung S5053 Repair

Sometimes when I replace the y-sus I run the test patterns first for 10 mins without the main board.
This way you know that if something disastrous happens it won't damage the main board.
It's not 100% necessary but I like to be cautious. :-)

[MaxAsh]

Re: Samsung S5053 Repair

Sometimes when I replace the y-sus I run the test patterns first for 10 mins without the main board.
This way you know that if something disastrous happens it won't damage the main board.
It's not 100% necessary but I like to be cautious. :-)

I'll have to play the noob card here and ask for some clarification on that once I get the board haha. Guessing I can figure it out from the service manual, but I've been wrong before.

Double-checking the Y upper/lower buffer testing: I found no shorts using the method in the video (probe on Main-to-Buffer ground connector pin, other probe to check for shorts across all IC termination points on both sides of buffer connections using the slow-drag method). Is there anything more I should test on the buffer boards, or is that pretty much it to ensure they're still ok? Visually I see nothing wrong, but I just want to make sure that's the only test I need to do on the buffers.

Also - would it be smart to test the new Y-sus WITHOUT the buffers attached initially?

[tom66]

Re: Samsung S5053 Repair

There is no way for the sustain to damage the main board, as far as I am aware, so I would not worry about that.

[MaxAsh]

Re: Samsung S5053 Repair

There is no way for the sustain to damage the main board, as far as I am aware, so I would not worry about that.

Okay. So I'm good with the plan to perform Y-sus replacement, hook it up, but disconnect Buffers initially and turn the TV on?

I've already tested everything with the Y-sus and Y-buffers disconnected and the TV runs fine (audio works, etc, just no picture). So I'm thinking add the new Y-sus, turn it on again, see if everything holds okay. Turn it off, add the buffers back in, turn in on and cross my fingers? I'm just paranoid that there's more I can test on the buffers. I don't want them to blow the new Y-Sus, but the short test I performed showed the ICs as okay.

[MaxAsh]

Re: Samsung S5053 Repair

Just a quick bump to see if anyone has further thoughts on this, or anything else I should test before I replace the Y-sus tomorrow.

[MaxAsh]

Re: Samsung S5053 Repair

Just a quick post to let everyone know it worked! Replaced the Y-sus board today and bam, the tv came right on. Looks great, but wow do these older non-fan plasma screens run hot. Thinking about selling it (and my 7 year old LCD) and using the profit to help buy a newer LCD.