Samsung PN50550T Won't Turn On!

[coppercitycomputer]

Greetings everyone I am hoping to get some help getting this Samsung PN50550tf2 50” plasma TV from 11-2009 going.

The guy that was throwing it away, said when he went to turn it on, it would just click a few times and refuse to do anything more. I got it home and it clicks a few times when you plug it up. Then when you try to turn it on, the power LED flash's 5 times then go's out. He said he had a local tech look at it and was going to cost $350.00 to fix and had two bad boards. I know this tech, he is worthless, so I throw out what he has to say. I have yet to pull the back off and look for bad caps or anything screaming “I'm Bad”. I don't want to throw a lot of money at this TV, I am able to do component level repairs.

Thought I would get this thread started and see if anyone has any pointers or things to check, thanks for any and all help.

[un4givintoo]

Re: Samsung PN50550T Won't Turn On!

take the back off and check the tops of the caps first if they are bulged or leaking out solder old ones out and new ones in i picked up a lg 42 at a local thrift store a few weeks ago and fixed itnow im hooked.

[Glitcher]

Re: Samsung PN50550T Won't Turn On!

The model number you provided is misspelt I think.
But common problems with those Samsung plasmas and clicking would be a bad x/y-main boards

[coppercitycomputer]

Re: Samsung PN50550T Won't Turn On!

Glitcher, how would I go about finding out what board is bad? What fails on the boards? Yes the model number is correct!

[tom66]

Re: Samsung PN50550T Won't Turn On!

It's not correct, there's a missing letter between PN50 and 550T, probably "A", or "B".

[coppercitycomputer]

Re: Samsung PN50B550T Won't Turn On!

My mistake it is a B, here is a photo of the tag. How do I go about trouble shooting it?

[coppercitycomputer]

Re: Samsung PN50550T Won't Turn On!

I removed the back and had a good look at things, nothing appears to be bad. I started unplugging things like the X and Y boards no effect on the problem. I unplugged the controller and TV tried to turn on and even made the start up sound. So it is safe to say if I replace the controller the TV may run? I don't think the screen tired to start? Is that normal?

[tom66]

Re: Samsung PN50550T Won't Turn On!

What is the "controller" you refer to?

[coppercitycomputer]

Re: Samsung PN50550T Won't Turn On!

It sits in the middle of the TV with all the flat ribbon cables connect to it!

Ebay Item 190940044723

[tom66]

Re: Samsung PN50550T Won't Turn On!

With all boards connected, turn the TV on and note if the indicator light on the control board flashes.

Does it flash continuously - about once a second - or about once every 5 to 7 seconds - or something else?

[coppercitycomputer]

Re: Samsung PN50550T Won't Turn On!

The board has two LEDs one would come on the other would flash a few times and then they both went out and the TV was dead.

With all boards connected, turn the TV on and note if the indicator light on the control board flashes.

Does it flash continuously - about once a second - or about once every 5 to 7 seconds - or something else?

[coppercitycomputer]

Re: Samsung PN50550T Won't Turn On!

Bump!! Any one have any more help on this set? Thanks

[arj1231]

Re: Samsung PN50550T Won't Turn On!

you could try to force on procedure. on logic board there should be four jumper pins. place jumper wire between #3&4 pins. on main board find ps-on wire, unplug wire harness from connector and short out ps-on wire to ground. power on , it should do a few self video tests

[tom66]

Re: Samsung PN50550T Won't Turn On!

As above but you also need to jumper VSON to 5V with a 100 ohm resistor.

[coppercitycomputer]

Re: Samsung PN50550T Won't Turn On!

No change, if I am doing it correctly, I think that's the right resistor. The front LED light stays on when its in this mode but the TV won't power on, Unplugging the other boards X Y and input, has no effect. If I unplug the controller power lead it makes the start up noise and try's to turn on, that is without the jumper and short and resistor.

Any more ideals?

[Alastair E]

Re: Samsung PN50550T Won't Turn On!

Check for shorts on the Vs line of both Y-SUS and X-SUS boards. Disconnect the PSU from the boards, and check resistance from the socket pins on the board to chassis/deck, should be pretty high resistance (Several 'K' ohms) after an initial low reading of a second or so--while the caps on the tested board charge via meter.....

Without the control-board connected, the PSU will not supply the Vs, Va etc but will supply the mainboard voltages--hence the chime and apparent life from the set.

I wouldn't waste dosh on a Control-Board without being certain that the fault wasn't elsewhere

[coppercitycomputer]

Re: Samsung PN50550T Won't Turn On!

The Y board very quickly go's to "1" on my meter set to 2000K. On the X board the number slowly increase's. What does that mean?

[tom66]

Re: Samsung PN50550T Won't Turn On!

In the photo above, are you jumpering both VSON and PSON? Any relay clicks?
Note, I've had a bad control board before, as has John on this forum, but it's overall quite rare.

[coppercitycomputer]

Re: Samsung PN50550T Won't Turn On!

PSon is going to ground the chassis VSOn is going thought the the resistor to 5.3V while still plugged to the controller.

Yes the relays still clicked.

In the photo above, are you jumpering both VSON and PSON? Any relay clicks?
Note, I've had a bad control board before, as has John on this forum, but it's overall quite rare.

[coppercitycomputer]

Re: Samsung PN50550T Won't Turn On!

So does it sound like the contoller is bad or?