Short on X-Sus board. Repair or replace?

[caphair]

I'm not that familiar with plasma tv's but I figured out the X-Main board has a short on it.

A bunch of transistors mounted to a heat shield along with caps etc in parallel measure shorted. I've yet to narrow it down to which component/s it actually is

My question, is it ok to simply replace the faulty part/s or best to replace entire board as whatever was shorted would have stressed anything else in parallel?

Also, what does the X-Main board actually do?

And a final question, is it ok to leave a plasma tv screen side down on a bed for a while (few days to a week) or should it always be vertically standing?

[tvtimmy]

Re: Short on X-Sus board. Repair or replace?

What is the model # of your Samsung plasma tv? Looks like a 51". I have fixed lots of them with just a few transistors. Maybe a board can be found cheap enough on ebay.

[tom66]

Re: Short on X-Sus board. Repair or replace?

My question, is it ok to simply replace the faulty part/s or best to replace entire board as whatever was shorted would have stressed anything else in parallel?

Replace all components in a given group - so if there are other transistors in parallel with the shorted ones, it's good practice to replace those. Other transistors on the board should be okay if not showing obvious shorts.

It is also worth checking the Y-main for failed components if the X-main is connected to it directly, and shares an energy recovery path. Clues would be pins marked "ERC" on a connector, that is connected to the Y-main.

Also, what does the X-Main board actually do?

Many functions. It supplies the common electrode drive waveform to the panel. This helps with sustaining (emitting light), resetting the panel (erasing pixels on each cycle) and initialising the panel (allowing it to be written and start emitting light.) On some plasma panels, the X-main and Y-main are chained together into an ERC resonant circuit, so they recover energy between themselves to improve the efficiency of the panel.

And a final question, is it ok to leave a plasma tv screen side down on a bed for a while (few days to a week) or should it always be vertically standing?

Yes this will be absolutely fine. There are myths about transporting plasma TVs but they are basically just sheets of glass. Whatever you can do to a sheet of glass, you can more or less do to a plasma TV.

[caphair]

Re: Short on X-Sus board. Repair or replace?

It's a S50HW-YB06

Are any other circuits at risk of being faulty from the short?

[caphair]

Re: Short on X-Sus board. Repair or replace?

"Replace all components in a given group - so if there are other transistors in parallel with the shorted ones, it's good practice to replace those. Other transistors on the board should be okay if not showing obvious shorts."

Does this also include any capacitors in parallel?

[tvtimmy]

Re: Short on X-Sus board. Repair or replace?

You posted the plasma panel number. Your tv model number should start with PN.... It is on the back cover. Any way, if you just want to get it running, go to shopjimmy.com and look up your x-main model number. Then look it up on ebay for the cheapest repair option. If you want to learn how to fix it send the correct model numbers and we will go from there.

[tom66]

Re: Short on X-Sus board. Repair or replace?

"Replace all components in a given group - so if there are other transistors in parallel with the shorted ones, it's good practice to replace those. Other transistors on the board should be okay if not showing obvious shorts."

Does this also include any capacitors in parallel?

no

It's a S50HW-YB06

Are any other circuits at risk of being faulty from the short?

I have no idea, I don't have an eidetic memory of every Samsung PDP out there.

You need to trace out the ckt and see if there is an energy path between the boards, it will be like a large current path that is not Vs, Ve, or GND. Will generally occupy multiple pins on a connector.

[tw2005]

Re: Short on X-Sus board. Repair or replace?

Looks like Samsung BN96-12950A (LJ92-01727A) X-Main Board
Example model would be : PN50C450B

Shopjimmy has about a hundred of these @ $24.33

Personally I would not even bother at that price to repair the board and here's why.

I have one and shorted on it Q4104,4302 ,2 IGBTs I think were RJP30E2 and also 2 FETs @ Q4401,4402 I don't remember what the originals were.

So i replaced all these with other IGBTs I had more than capable of the current and voltage.

First time , ran for 2 minutes, pop. the 2 IGBTs were shorted again. Tried again this time with IGBTs higher in current rating by 10 amps and higher voltage.
I got an hour out of it and I noticed the heatsink was hot enough to give you a burn.

So with a lack of experience with these I've bailed on the rebuild. I can only guess what the issue may be, bad caps? Should i have replaced the driver ICs (probably) Is the ymain somehow tied into the failure ? (who knows)

Not saying you won't succeed but consider the what ifs.

If anyone is an expert on rebuilding these or got sure tips to stop it failing, I'm all ears as I'd love to fix it. Could get a board but a little expensive to get one here.

[tw2005]

Re: Short on X-Sus board. Repair or replace?

Anyway, your post has made me try again, I've just subbed 45G124 Toshiba IGBTs which are a 400V 45A rating, and this time I've replaced both 73711 driver ICs with IRS21850S as they are a direct match plus I have a LG Ysus which had not shorted just open cct transformer so all the bit should be good.

It's up and running t, too early to count the chickens though. I'll report back with what happens

[tw2005]

Re: Short on X-Sus board. Repair or replace?

And , it popped, maybe 10mins. Anyway, good luck with your repair.

[tw2005]

Re: Short on X-Sus board. Repair or replace?

After reading another recent post on someone fixing a Ymain from this model with a bad HV cap I thought I'd try the ol shotgun approach..



1 hr 40mins runtime . A new record, previous was about an hour.

Running at full white, too early to claim victory.

[caphair]

Re: Short on X-Sus board. Repair or replace?

After reading another recent post on someone fixing a Ymain from this model with a bad HV cap I thought I'd try the ol shotgun approach..



1 hr 40mins runtime . A new record, previous was about an hour.

Running at full white, too early to claim victory.

So you ended up replacing all caps and shorted IGBTs? I'll just buy the board as I don't have any of these as extras so the price of components alone would probably equal just getting the whole board

You have the same exact model Tv with same issue?

[tw2005]

Re: Short on X-Sus board. Repair or replace?

So you ended up replacing all caps and shorted IGBTs? I'll just buy the board as I don't have any of these as extras so the price of components alone would probably equal just getting the whole board

You have the same exact model Tv with same issue?

Same board, common fault Xmain shorts, there's a firmware upgrade available.

I'm just giving a real example where replacing the shorted parts did not work out for me.

I only kept trying because it was giving me the poops. If I had the right gear maybe I could nail it but yeah $24 or a lot of work. I love component work sometimes you just got to be practical.

One thing I notice is the amount of heat off the heatsink and that heat goes straight into those big green caps which heat up a lot.

That's not quite all the caps, I left the ones on the side where the transistors were not failing.

[vinceroger69]

Re: Short on X-Sus board. Repair or replace?

is your set still running tw2005 now you have replaced all of those capacitors

[tw2005]

Re: Short on X-Sus board. Repair or replace?

is your set still running tw2005 now you have replaced all of those capacitors

Standby

[tw2005]

Re: Short on X-Sus board. Repair or replace?

is your set still running tw2005 now you have replaced all of those capacitors

I think so

[vinceroger69]

Re: Short on X-Sus board. Repair or replace?

thats good then hopefully people will read this thread and also replace all the capacitors certainly looks a nice picture on that tv

[tw2005]

Re: Short on X-Sus board. Repair or replace?

thats good then hopefully people will read this thread and also replace all the capacitors certainly looks a nice picture on that tv

I hope they find a good board but it does appear if it fails soon after the repair and stuck, yeah I guess. There some cheapies around and almost considered importing, bit nervous with the board failing, ruins the confidence.

I just wish I had better scientific evidence to check the caps. Ther's nothing visual and nothing leaping out doing an ohms probe but I will presume something changes once running and heats up.

I had a 42 which we grabbed as aworking giveaway. probably been sitting, powered it up and it went off like a cracker.

Though the worst expecting fried IGBTs, was in fact one of those 330 pf blue caps total charcoal, no other failure, cap replaced, carry on. LOL.

None of the blue caps have been done on the side those large red polyesters are.

Overkill but I'd had enough and went CRAZY! I'm waiting for it to fail, fluke repair though. not much left on the board to be honest

[tom66]

Re: Short on X-Sus board. Repair or replace?

Very weird, cannot explain why replacing the caps would be necessary unless one was shorted. Tried testing them?

[tw2005]

Re: Short on X-Sus board. Repair or replace?

Very weird, cannot explain why replacing the caps would be necessary unless one was shorted. Tried testing them?

Nothing shows shorted, don't have a cap meter or ESR. Only change this time was the caps and the difference is noticeable.

Are'nt caps affected by frequency as well? Assuming something goes out of whack with heat and frequency presenting equivalent of a short?

All ears on your theories. Would love to test them and be able to say yep this sucker here.

Anyway, had about 4 power cycles and 12 hrs run time now