Samsung PN43D450A2D help needed

[tom66]

Re: Samsung PN43D450A2D help needed

Looks OK. Make sure the ribbons go in properly and are fully seated. Since the electrode is common - all rows on the panel are connected to the same point - I don't see a problem.

[Krenzy]

Re: Samsung PN43D450A2D help needed

Good because that looks like it'd be a pain to replace, but damn, because we still don't have a root cause of this issue.

[Shinju]

Re: Samsung PN43D450A2D help needed

I would look at the ribbon connection to the glass, it's obvious the person that ripped those out did it with force and it's possible that it might have damaged there too.

[Krenzy]

Re: Samsung PN43D450A2D help needed

The connections on the glass have no wear whatsoever, but after turning it on and having the fault occur again, I noticed the Main board is noticeably warmer than the other boards, after only one minute of use. Is this normal?

[tom66]

Re: Samsung PN43D450A2D help needed

The main board was eliminated from being at fault previously by doing the control board test.

[Krenzy]

Re: Samsung PN43D450A2D help needed

Right. What should I look at next? The only two things I haven't replaced are the Y buffer and the two buffer boards tucked into the bottom of the unit (E and F buffers?).

[tom66]

Re: Samsung PN43D450A2D help needed

I don't really have any great suggestions. If it were my TV I'd have the scope on it, checking for any anomalies before shut down which might indicate a fault.

You can still try the bulb test, it's possible you were sold a bad PSU, although I admit it's a stretch of thinking.

Also, might be worth checking X-main and Y-main connectors for heat/burn damage, in case they do overheat (I have a Samsung smart LED shutting down due to overheating main board power connector.)

[Shinju]

Re: Samsung PN43D450A2D help needed

These gremlins are terrible! Since the YDrive buffer is cheap I would try it as a last ditch effort.

I have had a couple of these and all have been the xmain and once repaired/replaced they worked fine. One I kept is still good my strong.

Keep us posted!

[Ijaz Ahmed]

Re: Samsung PN43D450A2D help needed

Right. What should I look at next? The only two things I haven't replaced are the Y buffer and the two buffer boards tucked into the bottom of the unit (E and F buffers?).

This is an interesting case. I think for some reason, your panel has started drawing more current which the power supply and X/Y sus boards can not provide thus triggering some protection or as tom66 has suggested that it might be PSU not able to supply the demand.

Another test you can try is to remove all the Flat cables (from panel to Y-Buffer) except the top one. This will lower the load by 80%. Now run the test pattern by shorting 3-4 on jumper at T-Con (remember to disconnect the LVDS cable from Main AV to T-Con).

If you are able to get good/bright patterns then attach more cables to Y-Buffers one by one and see how much portion of screen it is able to drive.

[Krenzy]

Re: Samsung PN43D450A2D help needed

Alright, well, I gave Ijaz's advice a shot, and have some interesting feedback.

First, I tested each ribbon sequence, one, then two, etc. The display would not show a picture unless two or more ribbons are plugged in. Interestingly, when one or two ribbons are plugged in, there is no buzzing sound coming from the X and Y boards; 3 cables and more, the buzzing returns. I discovered when two, three, or four cables are plugged in, I can select the Media P. button on the remote and have the blue screen pop up. Five and six cables plugged in and the TV faults out to a black screen when I hit that button.

No option, from 2-6 cables plugged in, let's me run the Anti Burn scrolling test; it simply faults out like usual. Any ideas?

[Krenzy]

Re: Samsung PN43D450A2D help needed

Hopefully that post isn't too confusing.

The long and short of it: I still cannot run the Image Burn scrolling option, whether there are 2 or 6 ribbon cables installed onto the Y buffer. However I did notice the ability to use the Media P. button on the remote, and have the screen show up without causing a fault, when I had 2-4 cables installed...over that trips the fault again. I also noticed the boards don't buzz when there are only 1 or 2 cables installed. Not sure if that's normal or means anything.

[tom66]

Re: Samsung PN43D450A2D help needed

So, any combination of ribbons works? You could insert cables 1,2,3,4 and it works, or 3,4,5,6 and it still works? That seems to indicate there isn't a panel fault, but somehow something is unable to take the full display load.

BTW, the set not turning on with only one or two ribbons is normal, due to the ER circuit becoming imbalanced, it relies on the right display panel capacitance connected to work properly.

Really odd fault you have here!

[Krenzy]

Re: Samsung PN43D450A2D help needed

Correct, any combination seems to work. So am I to assume the buffer is okay? Forgive me for not being electronically knowledgeable, but what do you think this leads back to? PS Board? Should I open a claim with SJ to have my board replaced?

[tom66]

Re: Samsung PN43D450A2D help needed

Correct, any combination seems to work. So am I to assume the buffer is okay? Forgive me for not being electronically knowledgeable, but what do you think this leads back to? PS Board? Should I open a claim with SJ to have my board replaced?

This fault is pretty rare so the chance of two boards being bad is low, but perhaps possible. We could rule out the PSU using the light bulb trick, but I'm not sure if you are confident doing that. I'm reasonably sure your buffer is OK.

Could you try the test pattern (pins 3-4) again with some ribbons out? This would confirm the control and main board are OK.

[Krenzy]

Re: Samsung PN43D450A2D help needed

I sure can! I'll try the test pattern when I get home.

I'd like to try the lightbulb test, but honestly I'm not sure I'm understanding it. Is there a diagram somewhere? I'm a much better visual learner, typically.

[freakaftr8]

Re: Samsung PN43D450A2D help needed

do me a favor on the Y sustain there's a small connector going down to the bottom of the panel that controls the C buffers (bottom of the panel). Can you disconnect that grey cable off the Y sustain board and try powering up the TV? Does it stay on?

of course you do this after you tried doing the test pattern like Tom suggested. this is of course if the test patterns do not work

[tom66]

Re: Samsung PN43D450A2D help needed

Just be very careful with that connector. Wait at least 5 mins before plugging/ unplugging or you could kill the panel (pottery potentially)

[Krenzy]

Re: Samsung PN43D450A2D help needed

Ok. So first, I redid the tests from last night, as out lines by Ijaz, because I had forgotten to unplug the main to control cable. The tests yielded nothing, no pattern was visible with any combination or ribbons. I then tried what after8 suggested, and again, nothing showed up on the screen. However, I can report that the backlight indeed works, and when I hot the Media P. button on the remote, the backlight to brighter. What any of that means, I don't know.

[tom66]

Re: Samsung PN43D450A2D help needed

That is pretty much what is expected, how does the set behave with the Va cable (to the boards on the bottom) connected? Again make sure to unplug set for at least 5min before connecting this cable.

[Krenzy]

Re: Samsung PN43D450A2D help needed

Ok I tried something different, and unplugged all the cable plugs, inspected them for burning/wear (found none) then reinstalled them, seating them firmly. I had the top and bottom y buffer ribbons unplugged (4 plugged in), and I could actually run the Scrolling test!! It didn't kick out!

I took it a step further and plugged my phone into the TV via HDMI, and played the only video I had saved Ok my phone. It worked!! I went further, realizing the video was low quality, I decided to go onto YouTube and stream an HD video. Once I tapped the YouTube app link on my phone, the TV faulted out again.

Now no matter what I do, repeating the cable seating I did before, no luck. For about two minutes, without the top and buttom cable installed, it worked as it should. I don't know why or what caused it to fault out again.