Grundig 55 GUB 8860 - bad T-Con or bad panel?

[Ierwin]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

I have an update but at the moment it is not a good one:
I did some trial and error with various USB sticks and SW versions, pressing buttons, pluggin in, plugging out, never got anything on the screen.

I found out that pressing the "+" Button while plugging in with the USB stick in USB1 caused the TV to do "something". It briefly turned on the backlight, like it was starting and then shut off (all within 5 Seconds or so).

I figured maybe (I know you doubted that, but MAYBE) the T-con IS broken. So I unplugged the left ribbon again and performed the update procedure.
For a very short moment, not more than a second the large white letters and the progress bar of the software update screen were visible on one half of the screen.
It was really just a short flash, I only know it was the update screen, because I recognized it from some of the PDF guides.

I powered the set up once more with the ribbon disconnected and got to the menu again on half the screen. I am not 100% sure but I think the menu looked different from before. It had colorful Icons of Netflix or YouTube that I do not recall heaving seen during my cooling spray tests.

I connected the ribbon again and tried to install the old firmware.

And ever since then it has gotten worse.
I am not getting any picture at all now. Not even with the ribbon disconnected.
When I start the set and push the menu button on the remote the backlight gets brighter but nothng is visible on the screen

[Diah]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

do it the way you worked on the last firmware.. when you have saw what you saw before go to access the panel buffer boards... show here clear photo on both side

[Diah]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

yours chassis servive manual..read page 112

[Ierwin]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

So since I have 12V on the TCon Fuse the next step would be to check "L402" and "Tcon_On". I dont know where those are

[Ierwin]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

It also says in the manual to update the panel.bin and there ist a description how this file has to be placed inside a folder on the USB stick.
I do not have a panel file and all the directories in BIN_FILES are empty

[Diah]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

It also says in the manual to update the panel.bin and there ist a description how this file has to be placed inside a folder on the USB stick.
I do not have a panel file and all the directories in BIN_FILES are empty

Arçelik_Beko_Grundig_Released_Panel_Files

[Ierwin]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

thank you so much!
But how do I find the panel type? I was hoping it was on one of the bar codes but havent found a mathcing number yet

[Ierwin]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

according to the small sticker on the back I think I have a 55C46 Panel. At least that is the number that comes closest to the filenames in the zip.
But no file for that in the zip

[Ierwin]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

In the Service Manual is says:
Updating panel file
Inside of the BIN_FILES folder must appear
as below. Select the appropriate panel file
from O2_PANELLER.rar in the WEB folder.
Copy the file in the panel file folder and
paste it into the Keys folder.

So if you actually have access to that "WEB folder" that would be the file to look for

[Diah]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

both the firmware you downgrade and update didnt have panel.bin at panel & key folders so it mean the process will write the firmware with out touching the sector of panel data on eeprom. howver when it flashed the firmware it will reset the eeprom so the panel data will remain.

did you try to press the menu ? did some things apear on screen... did the backlight lit more high when you press menu ???

[Diah]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

according to the small sticker on the back I think I have a 55C46 Panel. At least that is the number that comes closest to the filenames in the zip.
But no file for that in the zip

the panel ID you can find ir at other small sticker at the middle top of the chassis where written on it GRUNDIG

[Ierwin]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

pressing menu the backlight goes brighhter but nothing apears on the screen.
I have never had a panel.bin on my USB stick, so it should never have overwritten. But because it stopped working after one of these flashing attempts I think the panel setting might have been deleted.

I found the ssticker on the chasis (fun fact: couldnt find it before because my multimeter was standing on it ).
But the number is the same as the small sticker on the back: 55C46P

[Diah]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

pressing menu the backlight goes brighhter but nothing apears on the screen.

okay,,, you need to inspect the LVDS cable and the 2 ribbon cable under good loop. the material they used on this TV are the cheapest one with bad quality easy the contact pin after 1-2 time take them out from the socket will brocken

[Ierwin]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

Okay so I measured all the ribbons with a continiuty tester (beeping).
I slowly draged the probes over the contacts of the connectors on each side.
I admit I did not take the time to probe each of the tiny contacts perfectly individually so if lines are shorted I wouldn't know. But at least I did not find any broken lines

[Diah]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

Okay so I measured all the ribbons with a continiuty tester (beeping).
I slowly draged the probes over the contacts of the connectors on each side.
I admit I did not take the time to probe each of the tiny contacts perfectly individually so if lines are shorted I wouldn't know. But at least I did not find any broken lines

Okay. now every things in place and follow the S.M after turn on and you press menu ( BL go brightness) measure voltage on pin 44 & 51 if you have missing V on 44 check the yellow parts.

[Ierwin]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

I found that section of the SM earlier and checked. I'm not at home right now and don't remember the voltages but both were equal.12V I think. Definitely not 0

[Diah]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

if both pins 44 & 51 have V. then my early post #8 are in place... you have drooped signal feed with main IC on main boards.

[Ierwin]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

So a loose BGA maybe? That's probably not repairable. But it would be possible that the connection was bad/failing and when I applied cooling spray the temperature stress on the soldering joints made it worse.
So nothing else to do but get a replacement Mainboard?

[Diah]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

So a loose BGA maybe? That's probably not repairable. But it would be possible that the connection was bad/failing and when I applied cooling spray the temperature stress on the soldering joints made it worse.
So nothing else to do but get a replacement Mainboard?

well. before i go to buy replacement MB the stress you mentioned could be, in this case i encourage you to packing the MB. in the oven with out air flew after you remove from the down side i think there are rubber legs

[Ierwin]

Re: Grundig 55 GUB 8860 - bad T-Con or bad panel?

What temperature do you suggest?
I once got a GPU back to life with this technique so I know it might be worth a try