Samsung PN50A550S1F does not turn on, relay clicks.

[EsqzMe]

I have a Samsung PN50A550S1F that decided to just quit the other night.
Screen went dark, no sound. The stand-by red light came on and relay started clicking intermittently.

I found 1 swollen/leaking cap on Y Main board. Everything else looked nice and neat. Replaced that cap but no joy.

Plug the power cord in and relay clicks multiple times then stops clicking, standby light no longer comes on. 1 green LED on the power supply board begins to blink in sequences of 7 times, repetitively.

Unplugged the Y Main with no change. Unplugged X Main with no change, Unplugged Logic Board with no change, Unplugged the input board and now the relay doesn't click and the green LED does not light up.

No swollen or leaking caps on this board (not many caps at all).
Any ideas or suggestions? I figure I'll try and find a replacement board, but is there something I am missing??

[tom66]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

When you unplug the main board (=input board) does the light on the logic/control board blink?

If so, see here
https://www.badcaps.net/forum/showpo...61&postcount=2

[EsqzMe]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

Updated info.
When relay is clicking the stand-by light is on, but goes off when relay stops and the LED on the power supply board starts blinking its continuous series of 7 blinks.

With the Main Board unplugged the green LED is on steady. No stand-by light and TV will not turn on.

The LED is on a small board mounted on the Power Supply board..see photo.

[tom66]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

I'm interested in the board to the right of the power board in that pic, the control/logic board. Does the light on it blink at all?

[EsqzMe]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

No light there. I was just looking at it to see if I could find the 4 pin connector for test jumps....

[EsqzMe]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

This board???

[tom66]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

Yes.
Do you have a digital multimeter?

You might have to jumper VsON and PsON to test PSU.

To do this, you will need two resistors around 100 to 470 ohms each, can you get hold of these easily?

[EsqzMe]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

Yes, I have a Fluke among other digital meters (and some old analogs as well !!!) resistors are not a problem.

[tom66]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

OK, disconnect the power connector from power to main, on the main board end. Connect the PS-ON to GND via one resistor and VS-ON to 5.3V via the other. Vs, Va should then come up. Then put the jumper on the control board and test patterns should appear.

[EsqzMe]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

Jumper between pins 3 and 4 ? I take it that would be the 5 pin open connector on the edge of the board...center pin appears to be dead end?

[tom66]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

It's the two row one, the pins will be labelled.

[EsqzMe]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

I'll give it a try later this evening and let you know. ....and thanks for your time and help!! I'm learning as fast as I can.

[EsqzMe]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

OK, disconnect the power connector from power to main, on the main board end. Connect the PS-ON to GND via one resistor and VS-ON to 5.3V via the other. Vs, Va should then come up. Then put the jumper on the control board and test patterns should appear.

Sorry to be so ignorant. Been a long time since I worked with electronics beyond the motorized vehicle stuff (like in the days of tubes)...

OK...I've got resistors, I've got jumpers, I've got a good meter, and I've located the #3~4 pins to jump....but:

where is the VS-ON and PS-ON??? I find a test point labled VS and one labeled Va on the power supply, but no PS-ON or VS-ON...

I figure ground is a chassis screw, but where should I tap 5.3 v power supply?

[tom66]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

VS-ON and PS-ON -should- be on the connector which hooks between them main and power board. It should have a little legend next to it.

[EsqzMe]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

I need better eyes.....

I'll get my magnifying glass out and have another look...and the 5.3v supply?

[tom66]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

Also on there though may be labelled 5.2 or 5.4V.

[EsqzMe]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

OK. I found the connector and legend on the power supply board. But it doesn't go to what I thought was the "main" board, so a clarification is needed please.

Here Is a pic of the 2 boards in question. The cable with the PS-ON etc goes to the board directly beneath the power supply.

Guide me oh Sensei ...

[EsqzMe]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

My iPad only loads one pic at a time...very frustrating. Here are the 2 boards in question. Which is the main and what is the other called

[tom66]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

The main is the one with video inputs on it.
The control/logic has the test pattern jumper on it.

[EsqzMe]

Re: Samsung PN50A550S1F does not turn on, relay clicks.

That is what I thought...so unplug cable from power supply to main board at the main board end. Install resistor jumps on the still connected lead from power supply to logic board, install test pattern jumper on logic board...plug in power??