Samsung UN55D6450 turns itself off and on endlessly, no blinks

[tibimakai]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

Ones I had a similar issue. I have removed the PS_ON wire from it's connector and I have measured it and it was cycling. I ended up replacing the mainbord.

[mmartell]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

I also tried to jump the LED backlights using the guide posted by Tom. I couldn't get anything to light at all, which worries me that it's not simply an LED strip failure. I suppose I could try replacing the power board first, but it's hard to get readings on this thing because it turns itself on and off all the time as soon as you plug it in.

I just realized I haven't measured the voltages that lead to the led strips with the inference that if the voltages are there and there is no light then I myself will be looking at prying the panel apart to get to the strips.

I'm guessing you tried simply removing the PS <--> MAIN cable and pkugging the set in to see if that fires your backlight ? (If the .pdf didn't apply to you, too)

[mmartell]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

NM I see in your earlier posts you make reference to the clicks. AFAIK with these power supplies the relay should click when plugged in with no load. Mine does not. Hmmm..

[mmartell]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

How about an audible "click" on power up ? I don't even see a relay on my PS and don't remember if it made any clicking sound when it was working properly.

[withalligators]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

no, with the main board unplugged, it doesn't cycle.

[mmartell]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

Ya small victory on the lvds cable, lol.

Refresh my memory, does your PS cycle even with everything disconnected from it ?

[withalligators]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

Good, luckily you didn't break it trying to figure it out. I've been there.

I also tried to jump the LED backlights using the guide posted by Tom. I couldn't get anything to light at all, which worries me that it's not simply an LED strip failure. I suppose I could try replacing the power board first, but it's hard to get readings on this thing because it turns itself on and off all the time as soon as you plug it in.

[mmartell]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

My lvds cable mystery is solved. There is a tab that must be flipped up first (exactly like the one's on the other side of the tcon) before you can squeeze and extract.

[withalligators]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

@johnboy: That would be fantastically helpful!

@mmartell: My LVDS connectors are much simpler than the one in your thread. It's 2 pushtabs on the side and that's it. Sorry.

[johnboy1313]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

@ Johnboy1313 Yeah, if you decide to go into the panel and let me know how you did it, that would be awesome. I'm still very reticent to damage this thing accidentally. If it turns out I need them, I'd love to buy your backlight strips!

I was going to cut the tape with a razor. The screen is already fubar'd. If it helps any, I'll try to see if I can carefully peel the tape back to save the adhesive. Maybe it can be resealed.

[withalligators]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

@ Johnboy1313 Yeah, if you decide to go into the panel and let me know how you did it, that would be awesome. I'm still very reticent to damage this thing accidentally. If it turns out I need them, I'd love to buy your backlight strips!

@mmartell, thanks for that link, I'm going to go test them as soon as I can, I'll get back to you about the LVDS cable, but as far as I remember, you just squeezed the sides to release it.

@splitcrete: I agree, I paid way too much, but it was bought from a friend who was sort of desperately down on his luck. I would never have bought it off craigslist for that much. It was more a little bit of charity in disguise.

[mmartell]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

I paid $200 for a 60" Kuro that cost $40 to repair and is now hanging on my wall rwplacing a 43" Pioneer that cost 10x as much. I think I stole that television from those poor people!

I paid $150 for the 55" D6000 referenced in this thread. Repair cost yet to be deternined. I think I could replace every board in it if need be and still get my money back.

I bought a 720p Samsung plasma for $40 that is awaiting parts. Now THAT tv I may have paid too much for lol but that's just because the hobby is addidctive and I was dry atm

So you see it's all relative.

[splitcrete]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

You paid way to much . The tv was broken . I always tell the seller if you think its an easy fix then you fix it. Then the price comes right down. There is always a tv some where needed to be fixed. Good luck

[mmartell]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

And here's the thread. The pdf from tom66 is in post#6.

https://www.badcaps.net/forum/showthread.php?t=34566

[mmartell]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

Btw do either of you have advice on how to remove the LVDS cable ?

[mmartell]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

@withalligators as per a service leaflet posted by tom66 in another thread there is a way to test the individual strips and there are access holes for that reason. Will post link shortly.

I have a UN55D6000 which won't turn on and am troubleshooting it atm in the other thread.

Between you, me and johnboy i think we should be able to fix one or two of these sets anyway.

[johnboy1313]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

withalligators, did you ever get this one sorted? I just brought home the UN55D6420 with a BN94-05038R main board with a smashed screen. I've unplugged the LCD from the T-Con and the set still powers on and off with the power button, including the backlights still light. I still have voltage at the T-Con as well. It appears that this set still works, minus the LCD. I'm more than willing to perform surgery on this panel and report back if that would encourage you to attempt the fix.

[withalligators]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

No, this one is sort of a sealed unit, unlike the other "fatter" panels I've been in. Once you get down to the bare panel, instead of having a metal frame that you can unscrew to reveal the LCD sheet, then diffusers, then the bulbs there what may be a metal frame, but it is sealed to the panel with adhesive backed black material. Almost like a heavy duty tape.

[tom66]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

You can most likely just take the front plastic off and metal frame, then try looking under the panel carefully by lifting it on the edge. Don't need to lift it out completely. You need a large flat surface like a workbench or bed.

[withalligators]

Re: Samsung UN55D6450 turns itself off and on endlessly, no blinks

From the bottom? I see a few access plates that have screws but I assumed they opened to get to the tab bonds. If not, how does one open this panel up? Do I cut the black adhesive material holding it together from behind?

Sorry if I seem reticent. I've cracked an LCD panel before putting it back together so I'm pretty nervous about doing it.