Samsung PN43D450A2D help needed

[tom66]

Re: Samsung PN43D450A2D help needed

There is one other test I can think of, but it is fairly involved. If you can find a way to attach two 120V light bulbs (in series) to the Vs output of the PSU (around 200V, two 120V light bulbs = one 240V light bulb) then that will provide a load to it, we will be able to see if the problem is that it cannot support load. (Plasma panels draw more power for brighter images, unlike LCD. This means the PSU might be able to work with a dim image, but as soon as a brighter image comes up, it shuts down.)

If not, perhaps you can just try replacing the PSU anyway, take a chance on it.

[Krenzy]

Re: Samsung PN43D450A2D help needed

Ok, I replaced the Power Supply board, that didn't fix it. I then installed a new Control board, no dice. Finally, I installed a new Main board. That didn't fix the issue. All board are new from ShopJimmy, they're kinda local to me. So either they're selling faulty boards, which I doubt, or...I don't know. What's next?

[Shinju]

Re: Samsung PN43D450A2D help needed

Bad Panel?

I did not read the entire thread, I have repaired one of these and they are VERY fragile. Your issue is a strange one, did you replace the Ydrive buffer too?

[Krenzy]

Re: Samsung PN43D450A2D help needed

Not the buffer, but the Y main board.

[Shinju]

Re: Samsung PN43D450A2D help needed

Not the buffer, but the Y main board.

Have you checked the buffer for shorts?

[Shinju]

Re: Samsung PN43D450A2D help needed

Tom66's video on how to do it!

https://www.youtube.com/watch?v=51SZsfH60EY

[tom66]

Re: Samsung PN43D450A2D help needed

I don't see a panel issue causing this. I just can't imagine how it could do this.

I noticed on the last D450 I worked on, that the X-main power connector had yellowed from all the Vsus current passing on just two pins. Perhaps over time this connector could overheat causing a Vsus sag? Worth taking a look.

We've had this odd, image-dependent fault pop up before on plasmas - and it's been a power supply problem in almost every case. I reckon if you tried playing "dark" content on the screen (mostly light grey with very little peak white) it would play for a while. Hence why your shut down occurs on the first test pattern displayed (white)

It's gonna be real fun when OLEDs come to the market proper - whilst plasmas vary from around 30-100% Vsus and 20-100% Va, OLEDs go all the way to zero on VCOM...

[Krenzy]

Re: Samsung PN43D450A2D help needed

If I did it right, then my buffer is fine. I could not get my multumeter to beep buy was able to see the number on the gauge to verify the process was working.

[Shinju]

Re: Samsung PN43D450A2D help needed

Odd issue indeed, I voted panel only because that's the only part besides the YDrive buffer he hasn't replaced yet.

this is a strange fault for sure!

[Shinju]

Re: Samsung PN43D450A2D help needed

Just for giggles, check each panel ribbon cable for wear damage, maybe something's grounding out?

[Krenzy]

Re: Samsung PN43D450A2D help needed

I inspected the ribbons and wires, nothing seems exposed or shows obvious signs of issue. Regardless, wouldn't a damaged ribbon or wire prevent the system from working fine before the issue hits?

When I plug in my HDMI cord to my phone to try and mirror that on the TV, it also trips it. What component is responsible for the image scroller/video? I tried tapping on all the heatsinks again, with no change.

[Krenzy]

Re: Samsung PN43D450A2D help needed

I did notice this: the two strips that plug into the X board have small tears in them. Would this affect it? How easy are they to replace? I noticed if I unplug one of them and hit the Media P button on the remote, I get a bright blue screen for had a second then the issue happens again, but it seems like it's more than I've seen before.

[Shinju]

Re: Samsung PN43D450A2D help needed

Well, I would be willing to bet that is your problem. Did you just rip those out or did you actually pull them out correctly because it looks like those were ripped out as those holes are supposed to be the locks to keep them in place inside the connector.

[Krenzy]

Re: Samsung PN43D450A2D help needed

This is how they looked when I released them. My guess is the previous owner is responsible for this. How can I fix this? And what are they called?

[Shinju]

Re: Samsung PN43D450A2D help needed

Well, those ribbons are permanently attached and glued to the glass panel I don't know how you can fix other than cutting them back but I would like to hear with Tom or someone with more experience as a first.

[Shinju]

Re: Samsung PN43D450A2D help needed

Have you inspeced the YDrive buffer ribbons too?

[Krenzy]

Re: Samsung PN43D450A2D help needed

Yes those ribbons on the Y are all intact, no tears.

[Krenzy]

Re: Samsung PN43D450A2D help needed

I'm hoping Tom or someone has any advice on what to do with those ribbons.

[tom66]

Re: Samsung PN43D450A2D help needed

Can you get a picture of the other side, the metal side, of each ribbon?

[Krenzy]

Re: Samsung PN43D450A2D help needed

If you need a better picture let me know.