Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

[Davi.p]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

Sorry, you have thermometer not ir cam..

Check this: https://youtu.be/CVsmwFAkf7I

[SoftwareHack]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

I see, I need to heat up the chip to get the solder to flow onto the pads that I can't access directly. I will give that a shot.

[Kilroy2k1]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

You can take a pair of side cutters, warm the chip up with your soldering iron and try to snip the top off it as if you were trying to decap the chip (removeing the top layer)
Then with the plastic package mostly broken you should be able to get to and heat the rest of the bits to desolder them.

[SoftwareHack]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

I was thinking along the same lines, but my mind went to my Dremel with a cutting wheel...but that's a bit more sketchy on collateral damage...

[Davi.p]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

No you.dont.need to warm the chip, you must warm the terminals with a big boob of solder,, you must wait a bit because it there can be a glue under.

[nomoresonys]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

A big boob of solder?...ok...Well now it's gettin interesting.

[SoftwareHack]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

I found my cheap soldering iron that I bought when I couldn't find my soldering equipment. It had a set of tips, one of which was a angled flat tip. I was able to heat up the chip enough to melt the existing solder and remove the diode array. Then cleaned it up with a wick and alcohol swab. I now have it plugged into a surge protector. This is the result! As an SF Giants fan, never been so happy to see Clayton Kershaw on the mound.

Thanks to everyone who helped me through each step, and getting me past my presumption that all power cycling issues were the same when I thought that I had isolated the issue to the mainboard.

My next project is an old Dell Latitude laptop with a dead screen...

[nomoresonys]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

Yep Kilroy nailed it, another fine save, nice job and good teamwork.

[SoftwareHack]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

Everybody who responded pushed me a little further into diagnosing and fixing the problem. So thanks to all.

[nomoresonys]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

I wonder if it will be ok down one diode array.

[SoftwareHack]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

My understanding is that it is for ESD protection.

[Kilroy2k1]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

Glad you have it sorted now. I posted the datasheet of the diode array so you could replace it if you want.
Little tip on these sets, turn the back light down about 15-20%,reduce the brightness and contrast down a few percent. Those 2 resistors that showed the pulsing will thank you.
Enjoy.

[Davi.p]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

Sometimes even with those protection diodes the surge reaches the delicate part of screen and nobody can save it, so to.protect it better it was good to replace the diodes.
Blob not boob, maybe boob is a tit?

[SoftwareHack]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

I saw that. I'll look at that when I believe that I can install one without messing it up.

I'll turn it down a bit when I figure out how to get the remote working again. It powers the TV on and off, but nothing else seems to work at the moment so I'm going to pair it to the TV again and see what happens.

[SoftwareHack]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

So backlight and brightness were both below 1/2, but contrast was 100%. I dropped contrast down 15%.

I'll order the part and look into installing it. Maybe I can practice on a junk board first.

[Davi.p]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

I don't know how an high contrast can ruin a screen...

[nomoresonys]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

Sometimes even with those protection diodes the surge reaches the delicate part of screen and nobody can save it, so to.protect it better it was good to replace the diodes.
Blob not boob, maybe boob is a tit?

Yep, I'd replace it just to be safe and try to protect all the work you just went thru.

[nomoresonys]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

So backlight and brightness were both below 1/2, but contrast was 100%. I dropped contrast down 15%.

I'll order the part and look into installing it. Maybe I can practice on a junk board first.

I set my un55 backlights on 7, that's as low as I can put up with.

[Davi.p]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

I hope that some virus takes away some unuseful idiots from this site..

[nomoresonys]

Re: Samsung UN55KS800DFXZA Ver. AA02 with the seemingly common power cycling problem

I hope that Corona virus takes away some unuseful idiots from this site..

Boy howdy...ME TOO. SPECIALLY the smartass PUNKS, that are WRONG WAY MORE than they are right...like the ones who thought this was a ccfl lit tv.