Dead Sylvania Big Screen

[Vitavox]

Help! My Sylvania RSJ410 AK02, ser # 64418468 just popped smoke! Actually, it popped, then it smoked. I was watching TV, when it gave a loud pop, the picture went dead and all the L.E.D.s on the front control panel came on. By the time I could get it unplugged (30 seconds), it smelled hot (burned). Not good, I know.
My question, does anyone have a guess about what happened. Power supply?
Any opinion about if its worth having repaired? It was top of the line in its day, and has some great audio features: 2 ins and outs, multi audio modes, pretty good internal amp and speakers, takes SVHS signal. I'd hate to see it go T.ts Up.

[hamop]

probable failure would be either the ihvt and/or the hv/focus block. both are high voltage areas . around 31kv .. a reputable shop could POSSIBLY get it going around the $200 mark +/- . call around for some "guesstimates" and go from there. bear in mind an estimate is just that. never know exactly what will be required till the process is completed.

73 y gud luck de hamop

[MannyE]

I see it as a blessing in disguise! My Toshiba TW56D90 has been going strong for almost 11 years now, and I can't justify even to myself, much less the boss, to get rid of it. The day it blows will be bittersweet, but less bitter than sweet. It just goes to show that calibrating with VE from day one really helps these RPTVs last much longer. I'm convinced that's what it was.

Now go get a new HD widescreen big screen like God intended for you to have.

[rylos]

It's the "magic smoke" that makes it work. Once you let the smoke out, it won't work until you put it back in.

Could be the parts already mentioned, could be a capacitor just letting off steam. Look at the boards. If you see anything that looks exploded, smoked, or swollen, that could be a clue. I could help more if you would post a sample of the smoke for me to smell, different types of parts have their distinctive smell when they blow up.

[Vitavox]

Well, darn. I forgot to catch the magic smoke. :sigh:
Actually, I'm just now getting around to taking the back off and watching it smoke, which I just did. (Been watching a literal small screen all summer.) I now know for certain the problem is on what is labeled the Power Supply Assmebly board, #88425 (or 88423) MDT 385. It is the large component next to the heat sink. (As indicated in the close-up pic.) The series of events is: Plug in, switch on, component glows yellow near the board, click, poof, magic smoke, unplug. Anybody have a lead on where I might find this board? It looks like it is all plug-in to the other boards. Yes, I see the label that says this is one of the high-voltage sections, and that the heat sink has a high ground potential. So, how would I discharge residual current? Will letting it sit for 2 weeks allow current to disipate?
Thanks for any ideas. :scratch2:

[dewickt]

Bet the HV transformer is bad, don't worry about discharge to much, the focus block will bleed the HV off of the tubes in less than a minute. This chassis is well known for killing HV transformers, best to find a junk set with a good panel.

[Vitavox]

Bet the HV transformer is bad.

Dewickt:
Thanks for the reply!!
Is the HV transformer the largest componet on the board, partially circled at the left side, right next to the heat sink? That's the part that glows and smokes. Beleive it or not, I found an identical set on the side of the road about a month ago. When I got it home, guess which board is missing? If you guessed the Power Supply, you're a winner. Unfortunately, I'm not.
Best price I've found for a replacement board is $226.
I'm not sure I want to spend that much for a part for an old set like this. But, of course it now seems I have a complete set of spare parts. And probably all working, since the only wires unplugged on the "roadside recovery" were the ones to the PWR Board.
Wonder if the transformer itself can be replaced on this board? Is there any way to know if its a common component, or came from the dark side of the moon? I don't see any numbers I can read on it. (Could be burned off, or covered with soot.) I have discovered this set was made by North American Philips. But, that doesn't mean these parts are readily available.
Anybody got one of these sitting around that you'd like to part out?
One thought I had was that if I do replace that board, this set needs a cooling fan. You can see the heat trails on the enclosure board above the PWR Supply in my pics. Seems excess heat builds up there...might be why this set burns up those boards. The back is perforated, but there's no convective flow. So, I'm thinking a small fan attached to the back perforations might help longevity.
V

[dewickt]

You picked the right part, the glow is it arcing, most likley to the core, it originally had a paper label with the part number that you will need to order a new transformer. If you can find the number check with www.mcmelectronics.com I seem to remember them carrying a firly large stock of them.
Yes that is a NAP set, was designed here in east TN where NAP used to have it's US engineering, NAFTA came along and we were closed down, my job moved to Mexico after 12 years.

[holmesuser01]

This board failed all the time when these sets were new. I replaced a bunch of them in the early 90's.

[Vitavox]

Terry:
Thanks for your thoughts. This set actually says it was assembled in TN. I am familiar with mcm. Since you seem to be intimately familiar with this set, what do you think of my cooling fan idea? I have a Sony 53" set that has a fan.

[dewickt]

They were never thought of as running hot in engineering, problem was a poorly designed HV transformer that was updated later in production with one that was bullet proof. I got to know the set later on when it came to repair them at a friends shop. I worked for NAP for 12 years, did the approvals and standards for CRT's and Yokes, can still set purity and convergence from scratch in about 2 to 3 minutes for a direct view set, used to teach the production people how to do it on the line running at a rate of 2000 sets per line per shift.
A nice quiet fan wouldn't hurt, just watch out for the dust, especially on the mirror and lenses.

[andy]

http://www.hrdiemen.com/products/index.php?command=viewPage&page=homesite

This company sold me a flyback that worked perfectly in one of those sets. Philips would only sell the complete board, not just the flyback. What ever you do, don't power the set up again or it will blow the horizontal output, HV output and power supply transistors (the large transistors on the three big heat sinks). I'm amazed it didn't do that already, but as long as it's not blowing fuses, they are probably ok.

Don't waste your time trying to find a used flyback, or board. Back when I fixed a lot of those sets, the flyback would fail about half the time within weeks of some other unrelated repair. The one used board I installed only lasted a week before the flyback went.

Have you ever had the CRT coolant changed? Every single one of those I worked on had tons of bacteria growing in the green and blue. This results in a very foggy picture.