Samsung pn51d550C1fxzc plasma died, hope to fix

[Hobb3s]

I have a Samsung pn51d550C1fxzc plasma (2 yrs old) that I believe has a bad x-main board. I was going to replace the whole board, but I can't source one, everyone is out of stock. So I've been reading through advice, troubleshooting methods, and common problems.

It's my first time troubleshooting a circuit board, but I think I've narrowed the issue down to my X-Main board, and one of the mosfets on it (toshiba 30g124 to-220) after a little multimeter testing. I'm a newb at using a multimeter, but I think I found a short.
I was just wondering if anyone has had similar experience with this model of television? or what their issue/repair was.

As well, should I replace all of the mosfets of the same model with new ones, or just the one I think is shorted?

Is there anything else you would recommend I replace a the same time?

One more question, I have been able to find the similar board with different revisions 1.2 & 1.4, would those work or is the revision important to proper operation?

The suspected dead x-main I have is this:
Model: 50'dh/df_XM
PCB: lj41-09422a
rev r1.3(11/06/20)
lj92-01759a
lj92-01763a

Thanks!

[Michale32086]

Re: Samsung pn51d550C1fxzc plasma died, hope to fix

If you can post a picture of the board in question, I might be able to dig up a replacement... I have a ton of plasma TVs flying around....

Michale

[Hobb3s]

Re: Samsung pn51d550C1fxzc plasma died, hope to fix

Here are some pictures of the board. One I pulled off a site that sells them, and the other is a close up of the info off the board taken from my phone.
Thanks for looking!

[tom66]

Re: Samsung pn51d550C1fxzc plasma died, hope to fix

Wow, this board is failing a lot. 4 or so posts in the same week?

The IGBT is bad if shorted, but there may also be other IGBTs bad in the same area. Often the IGBTs are arranged in half-bridge pairs, a high and low IGBT for the sustain voltage, for example. If you find the low bad, you must replace the high, and vice versa, unless you can be certain they are all ok. It's usually simpler just to replace them.

Also, I would always replace any driver chips which control the IGBTs, this is because in some cases the IGBTs can damage the drivers when they short. If this is the case, turning on the set with new IGBTs but old drivers would cause the new IGBTs to burn up, as they would be given incorrect gate drive. This will involve surface mount soldering work in most cases but it's relatively easy 1-layer PCB stuff, hard to do wrong.

[Michale32086]

Re: Samsung pn51d550C1fxzc plasma died, hope to fix

Here are some pictures of the board. One I pulled off a site that sells them, and the other is a close up of the info off the board taken from my phone.
Thanks for looking!

That board looks REAL familiar... I am fairly certain I have at least 1 or 2 flying around..

I'll be going to my shop tomorrow around 1400 EST.. I'll see what I can dig up and post here....

Michale

[Michale32086]

Re: Samsung pn51d550C1fxzc plasma died, hope to fix

Here's what I have...

Can't vouch for it's functionality... PM me your shipping addy and I'll get it to you. If it works for ya, then just cover my shipping and we'll be square...

Michale

[tom66]

Re: Samsung pn51d550C1fxzc plasma died, hope to fix

Michale, 'fraid that's a 720p board (probably PN51D450 or D490) and so probably wouldn't work in his 1080p set.
However, I think it would be possible to convert the 720p board into a 1080p one with a few modifications.

[Michale32086]

Re: Samsung pn51d550C1fxzc plasma died, hope to fix

I have a few more Samsung Plasma sets in one of my storage sheds.. I'll dig thru those...

[Michale32086]

Re: Samsung pn51d550C1fxzc plasma died, hope to fix

Nope, no luck.. That's the only one I have...

[Hobb3s]

Re: Samsung pn51d550C1fxzc plasma died, hope to fix

Thanks for trying.
I made the attempt to replace the fets I found shorted, but to no avail. I don't have the technical expertise to trouble shoot this board short of just replacing all the components. If I had more time I might, but my wife and the kids want our only TV back and working sooner than later. Now I have to figure out what to buy, obviously it won't be Samsung, I'm done with them.

[tom66]

Re: Samsung pn51d550C1fxzc plasma died, hope to fix

What did you use to repalce the FETs? You must use exact replacements.
Also it's often advisable to replace the driver chip that controls the FETs.

[Hobb3s]

Re: Samsung pn51d550C1fxzc plasma died, hope to fix

I replaced the fets with the same part number as was written on them. Toshiba 30g124. I don't have enough experience to identify which ones are the driver chips that you're referring too. I've attached 3 pictures, one of the back of the board, one of the front, and one of the fets including 2 I replaced. If you could point me to the driver chips, that would be very helpful.
Thanks!

[tpiton]

Re: Samsung pn51d550C1fxzc plasma died, hope to fix

Sorry to jump the thread. I've read quite a bit on the forum andI cant find the answer to my question. Will a SAMSUNG X-MAIN BOARD LJ92-01759A, LJ41-09422A / that PN51D450A2D will fit in my tv that is a PN51D550C1F ? It's all the same part number and the same version

Thanks

[rogerazambuja]

Re: Samsung pn51d550C1fxzc plasma died, hope to fix

Sorry to jump the thread. I've read quite a bit on the forum andI cant find the answer to my question. Will a SAMSUNG X-MAIN BOARD LJ92-01759A, LJ41-09422A / that PN51D450A2D will fit in my tv that is a PN51D550C1F ? It's all the same part number and the same version

Thanks

I'm not sure, but I think D450 model is 720p, right? If so I think it will not work.