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Ierwin · 05-14-2025, 02:47 AM

I connected TP_TRDY_1 and TP_TRDY_3 but still not get any picture with one side disconnected.
I also did a closer inspection of the COF on the side of the panel and indeed found visible damage on the topmost one on the left panel side.
Its hard t get a sharp picture because its so tiny but it looks like the foil teared.
If there is a broken line in that COF foil I am affraid I do not have the tools nor the skill to fix them.

I will try to get a better look at these things later....

Ierwin · 05-14-2025, 12:24 AM

Have not found those points yet, but I will continue to look for them.

I realized that the panel was sitting a bit odd in the frame and removed the front frame. I suspect that the tv had been tiltet upright with the back side removed and the panel slid down about 1cm due to its weight.
Still have not seen any signs of cracks, but theere has definetly been some stress on the COF cables on the side of the screen. NOthing to bad, but some were kinked a bit.
From how flimsy these things are I suspect the stress of the panel weight essentially pulling down on the side cables...

Ierwin · 03-11-2024, 02:57 AM

"suffer from BGA" you mean the soldering joints on the chip?

Ierwin · 03-11-2024, 01:24 AM

Now I also checked the factory menu (1999 + BACK).
It shows PANEL_ID 104 so I am starting to lean towards this not beeing the original MB and that some of the settings are wrong.
Or maybe the panel was changed at some point for the other version in the SM and the sticker wasnt updated...

Ierwin · 03-11-2024, 12:30 AM

New Problem:
I wanted to make sure that the set option is correct and performed the steps from the service manual shown above:
062598 + HOME + 040.
I think I misstyped the 040 when I first did this.

After the restart the screen was split in half, with both sides showing the same picture that should be fullscreen.

Since then I have üerformed the same process many times but it never changes back to normal.

Before I changed anything I made sure to perform every "write to USB" option the service menu has, so I hope I have the original...

Ierwin · 03-10-2024, 05:15 PM

Did a quick check on the wifi board when I realized it has very nice labeled test points.
GND to VCC reads 5.0V

Ierwin · 03-10-2024, 05:10 PM

I will check the 5v tomorrow.
For now I already found out that on the rear sticker it says "set option 040".
A Sticker on the inside that I assume states the panel type says "TPT580F2-PV5D.Q".

According to the service manual that should be panel ID 155

I checked the CSM and it shows the same serial number as on the back stricker and the correct set type wit the correct size.
Panelcode 155 is also set correctly.
It shows an Ethernat MAC Address but no Wireless MAC Address there (which makes sense because the mainboard cant communicate...

Ierwin · 03-10-2024, 03:27 PM

thank you for your input.
I removed the module but it seems to make no difference.
If the settings in the service menu have been messed with or the mainboard is actually a replacement that maybe came from a different size tv:
Is there any way to find working settings or fix this?

I will attach the log I recorded via UART...

Ierwin · 11-16-2023, 11:52 AM

Re: Samsung GU50TU8079U bad panel diagnosis

I read a bit about VGH and how it often causes Panel problems.
The VGH Testpoint on the left Panel board reads 0v when the U- ribbon is disconnected.
When I start the tv with the Ribbon connected the meter shows a voltage very briefly but the tv restarts before I get a reading.
If I had the schematics of the board I could check where the VGH comes from. Sice I don't have anything I might have to trace ist myself

Ierwin · 11-15-2023, 05:08 AM

Re: Samsung GU50TU8079U bad panel diagnosis

You are right, "U" describes it much better, lol.
I cleaned everything carefully and checke for bends.
Could not find anything unusual.

With the U ribbon connected the set still restarts before a picture comes on (backlight turning off and on again).

With the ribbon disconnected the program comes up and the sound is playing. Sometimes after a minute the sound cuts off, sometimes it runs for ages.
(I have been listeining to old baywatch episodes for hours, my brain...

Ierwin · 11-13-2023, 04:52 PM

Re: Samsung GU50TU8079U bad panel diagnosis

at that point I disconnected the mainboard and the backlight stayed on. Then connected the mainboard, disconnected ribon that leads to the panel board. Set stayed on. Then started taping until the set stayed on.
Whats strange is that none of this behavior has been constant.

inbetween it was perfecly fine without any tape and it ran for a couple days

Ierwin · 11-13-2023, 04:41 PM

Re: Samsung GU50TU8079U bad panel diagnosis

that is exactly what I measure about the GND connection. Only the center pins. No short to GND fro any other pin....

Ierwin · 11-13-2023, 04:37 PM

Re: Samsung GU50TU8079U bad panel diagnosis

right now it is sitting face down on my desk on blanket, yes. But of course I lifted it up to check the screen :P

I dont know what has caused this but the behavior now is different from what it started with.
1. When I got the set it rebooted after 2-10 minutes
2. after playing with tape and giving up it stayed on for hours with good picture except for 2-3 tiny lines
3. after a couple days it suddenly turned off and restarted immediately
4. playing with tape again I was able to...

Ierwin · 11-13-2023, 04:15 PM

Re: Samsung GU50TU8079U bad panel diagnosis

If I disconnect the C-shaped ribbon on any side the backlight stays on.
The sound stops after about a minute but it does not make a difference what side of the ribbon is connected.
with both sides of the ribbin connected the tv reboots right away, most of the time before any sound comes on, or a second after...

Ierwin · 11-13-2023, 04:00 PM

Re: Samsung GU50TU8079U bad panel diagnosis

with the ribbon removed completely the backlight stays on but no picture of course. The tv is currently set to some samsung streaming program via Wifi. The sound is not constantly on but without a picture its hard to tell if there is connection problem with the source or if the tv is not actually fullyfunctional.

I taped the 14 pins and the tv reboots again.
Which is strange because a couple days ago I managed to have it stay on with fewer pins taped but had black lines then.

Will...

Ierwin · 11-13-2023, 03:39 PM

Re: Samsung GU50TU8079U bad panel diagnosis

I did not use any water to clean but of course there might be moisture... I could evaporate using a heat gun and just carfully warm it up a little bit?

I also was able to read the marking on T15 and T16: 5R2P so obviously those are esd protection diodes... not saying I know what they are there for

Ierwin · 11-13-2023, 03:24 PM

Re: Samsung GU50TU8079U bad panel diagnosis

I went and carefully checked T16 and T15 again.
There seem to be several shorts across the pins left to right.

Before I rip them off as suggested I would like to undertsand what they usually do though. Could you explan what they are?

Ierwin · 11-11-2023, 10:14 AM

Re: Samsung GU50TU8079U bad panel diagnosis

Ich checked all the points with 2000Ohm Setting on the Meter.
All were higher except for 2 on the right side.
VGK @530Ohm but only one direction
VSS @1000Ohm

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