View Full Version : Got a free Plasma, need help!


Eric H
09-20-2015, 08:13 PM
A friend gave me his 2009 Panasonic TC-P50S1 Plasma set because it died.

I'd like to get it going for a spare if possible.

The set will power on and click, the fans run on high speed for a second then it shuts down and the light flashes ten times. I have to unplug the set for a while to reset it so it will power on again.

Following this rather lengthy thread I'm getting the idea the SC board might be the problem. http://www.justanswer.com/tv-repair/7lt8e-hi-i-panasonic-tc-p50s1-plasma-tv-2009.html#re.v/266/

If I disconnect the SC board I get the voltage at the power connector that slowly drops after it shuts down, the fans run at a normal speed, and it runs much longer before shutting down and then flashing code six (with the SC board disconnected)

Also if I plug the power connector back into the SC board I get a large spark and the voltage immediately drops to zero.

I would be willing to spend the money on a refurbed SC board if there was a high probability it would fix it.

rca2000
09-20-2015, 08:34 PM
Well..having worked on a LOT of these plasma sets a few years back (when they were NEW..)..I can shed some light on things...maybe..

You say you are getting 10 blinks ...and no power up.

WHen you disconnect that big connector--I think it is SC-1..do you THEN get about 200 or so volts on the other end of that cable at the P board--power supply--for a couple of seconds ?

ANd with the SC-1 connector CONNECTED...does that voltage stay LOW?

It is NORMAL on one of these sets for you to get a 6 blink code--if that ribbon cable is unhooked fomr the SC board.

ALso OHM the SC-1 connector--when the cable unplugged. if it shows LOW ohms..less than maybe 5K ohms...the SC board has some shorted IGBT transistors.. A VERY common problem on these sets.

Paul Knaack
09-20-2015, 09:14 PM
.........

Eric H
09-20-2015, 10:16 PM
You say you are getting 10 blinks ...and no power up.

Yes.

WHen you disconnect that big connector--I think it is SC-1..do you THEN get about 200 or so volts on the other end of that cable at the P board--power supply--for a couple of seconds ?

If I follow you correctly then yes, I didn't measure it at turn on but I measured it right after it shut down and there was almost 150 volts and dropping, like the capacitors were discharging, I took that to mean the Power Supply was turning on. .

I had the ribbon cable to SC-1 disconnected during this time. With SC-1 completely disconnected I get 6 blinks of the power light.

ANd with the SC-1 connector CONNECTED...does that voltage stay LOW?


When I plugged the connector back into SC1 or whatever number it is I get a nice big arc like it's discharging across a short and voltage drops to zero, this is with the set unplugged, just residual charge.

With SC-1 plugged in the cooling fans power up at a high speed, with it unplugged they spin at a normal quiet speed, like maybe they're tying to cope with an overload on the PS?

Eric H
09-20-2015, 10:19 PM
ALso OHM the SC-1 connector--when the cable unplugged. if it shows LOW ohms..less than maybe 5K ohms...the SC board has some shorted IGBT transistors.. A VERY common problem on these sets.

I see there are kits to rebuild the board on eBay but they are fairly expensive as well.

Did you replace the board or just the failed component?

rca2000
09-20-2015, 10:38 PM
I personally did NOT have much luck trying to rebuild Pana SC boards, Others may have...but the few times I tried...I got to watch my work go up i SMOKE..in only few SECONDS..(Never tried a "kit", just replaced parts that checked bad). So I usually replaced them...It is just ""too easy"..to "miss something"..that CHECKS ok on a METER...but does NOT work ok under POWER...on those SC boards !!

Eric H
09-20-2015, 11:52 PM
Sounds like I'd be better off getting a known good board then.

I did the resistance check you were asking about, the Blue and White wires are the only connector on this board other than the ribbon cable (disconnected in this picture) so I'm guessing that would be the one.

I read about 0.6 Ohms, basically a dead short so that would be bad right?

rca2000
09-20-2015, 11:57 PM
I GUARANTEE the board is SHORTED....if you are reading that on SC-1 connector. It has shorted devices on it. I HOPE the Buffer boards are not bad. You will not know that....till you get a good SC board.

Eric H
09-21-2015, 02:04 AM
That is my biggest worry, is there more wrong, and if there is will it fry a new board, I'll have to think about this one.
I can have the board repaired for $119 plus shipping, or get a kit with a million parts, some of which are surface mounted and hard to install for $40.

I may pull the board and poke around with a meter and see if I can identify any specific transistor that is shorted, however if I actually tinker with it and unsolder any parts then I can't send it in for repair later.

rca2000
09-21-2015, 12:02 PM
I am NOT going to lie to you and tell you..."go ahead...you will be ok".. It is LIKELY you WILL be "ok" by just replacing the SC board...but NOT guaranteed. It IS possible a buffer board has gone out too (these are the small boards next to the SC board on the left side) or even an SS board (the OTHER larger board on the OTHER side of the panel.). I WILL tell you though..a MAJORITY of these sets were fixed by thgis board.

But this is one reason so many have said "sayanora" to plsma technology. It's 'tendency to fail. Early on--plasma sets were touted to "last a LOT longer than a CRT set..we ALL know....how THAT turned out. This ans the FACT that they burn VERY easily..easier than ANY other type of display, are fragile(but to are LCD sets), use a LOT of power and are heavy...

But if it was MY set....it IS likely...I would attempt a repair..if for no other reason...than for the challenge. ANs a 50 inch Pana plasma shoud NOT be hard to sell..a LOT of people still like the picture they produce.

Eric H
09-21-2015, 08:25 PM
I understand it's a risk and wouldn't blame you if it doesn't fix it, I probably will go ahead and get the board rebuilt soon, part of it is just for the fun of trying to get it running, also being a Panasonic & a Plasma I feel it's worth fixing, if it was one of the lesser brands then probably not, it would seem like a waste to take it to the recycler.

I already have two Panny Plasmas one is slightly older than this one but is a higher end model, it has 10,000 hours on it without a hiccup, I think it has four or five cooling fans in it but they are so quiet I never knew about them until I moved it last year.

The other one was bought new in January 2014, fantastic picture but I wonder how long lived it will be, it seems to be built a bit cheaper.

I also have a Samsung 32" LCD set that cost me a whopping $26 when it was only three years old, $25 for the set, $1 for the capacitor, it's still running fine and gets a lot of use as a bedroom set.

If I get this Plasma fixed I don't really know where I'll put it, maybe the Bathroom :D Would two feet away from the "Chair" be enough distance?

Boobtubeman
09-21-2015, 09:36 PM
Never put a tv in the bathroom.... You may forget where you are and go out and pee on something during a commercial :D

SR