Samsung UN55D6450 turns itself off and on endlessly, no blinks

[withalligators]

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

I tried that, the relay clicked, but it wouldn't turn on with either unplugged

[aaronwt6]

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

It apprears to me that there are tow cables at the top of the power supply going to the LED strips. I'd start by powering the set up with one then the other unplugged (ones at a time). If it powers up with either or unplugged then its going to be the LEDs.

[withalligators]

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

How does one get at the LED strips? When the logo appears, it seems uniform. It's every flash after that where the backlighting seems uneven. Also, while the red LED seems to just turn off and on inverse to whether the screen is off or on, it blinks twice after each relay click after you unplug it.

[withalligators]

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

The whole shebang:

The main:

The power board:

TCON:

[johnboy1313]

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

The top of the screen is also brighter than the bottom as if that edge is lighting but the bottom isn't.

Could be shorted LED strip too.

This is where I would start. Try unplugging the LED strips one at a time to see if it will stay on. If it shuts off, plug that one back in and unplug the next one.

[capkid]

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

Yes, clear pics of the circuit board layout and what you see onscreen would be helpful.

[withalligators]

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

OK guys, I brought it home. When you first plug it in, the relay clicks and it turns itself on, and a quick Samsung Smart TV logo appears for less then a second and then it shuts off. A few seconds later the relay clicks again and the screen flashes on and then off instantly, with no logo. The top of the screen is also brighter than the bottom as if that edge is lighting but the bottom isn't. Pressing the power button does nothing. It will continue this cycle until you unplug it. At which point the relay will click on and off a few more times, but at a progressively slower rate. Any new ideas? I'm still thinking main but wouldn't be surprised if it were a component on the power board. would photos of any of these boards help?
Cheers,
Alex

[capkid]

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

It sounds fixable, and I'd be thinking main board, also. I'd probably buy it, although I'd have a hard time paying $250 (just my cheapness with regard to non-necessities ). It looks like a nice TV.

[withalligators]

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

It shuts off too quickly. Granted, I didn't have a video source hooked up, but sammys display a logo when they boot on, right? Anyway, this sounds fixable to me. Do you much smarter guys concur? I can pick up today or I have to wait a week.

Cheers,
Alex

[tom66]

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

I'd be thinking main board or t-con, is picture visible just as it cuts off? Could be shorted LED strip too.

[withalligators]

That's the simple gist of it, my friend has a Sammy UN55D6450 that when plugged in turns itself on (relay clicks, backlight turns on) and then instantly shuts itself off. A few seconds later it repeats this process. He'll let me have it for 250. What do we think? Seems fixable. Main board? I haven't opened it or anything.
Cheers,
Alex