Faulty display? Vestel TV

[Askic]

Hello guys,

My friend have Telefunken TV with probably faulty display. I need your advice from your experience, what could be wrong here.
Is it LCD display or mainboard? I assume that power supply module (17IPS20) cannot cause this? (the picture is in the attachment)
I also assume that all LED diodes in backlight are OK.
The mainboard is 17MB82-1a 10083714 23100546.

On the display there is no visible physical damage.

Thank you very much.

[nomoresonys]

Re: Faulty display? Vestel TV

See where the bar is, try squeezing the bezel with your fingers right there at the top, can also try slightly tapping the bezel there with your knuckle, not too hard, don't want to damage the screen or anything, see if the bar changes any.

[nomoresonys]

Re: Faulty display? Vestel TV

Might not be the same problem as this thread if it is I hope it isn't as bad with the tab almost tore off: https://www.badcaps.net/forum/showthread.php?t=84369

[budm]

Re: Faulty display? Vestel TV

Show us pictures of the whole backside of the TV showing all the boards so we can see if the tab bonding boards are on the top or bottom side of the panel.

[nomoresonys]

Re: Faulty display? Vestel TV

Good point Bud, they might be on the bottom.

[Askic]

Re: Faulty display? Vestel TV

Actually I have another one Tv with no backlight. I'm not sure whether the problem is on 17IPS20 or backlight LED. Idea is to combine these two to to have one TV. I'm trying to figure how to do this with least work. I think the best would be if I move metal chasis (LED MB and supply) from TV with display issues to the TV with no backlight issues. Maybe try to exchange Tcon long thin PCB first.

[budm]

Re: Faulty display? Vestel TV

"17IPS20" is the blank PCB part number, you need to match the PCB Assembly part number as printed on the bar code sticker since the LED driver Voltage between the 2 PCBA may not be the same. 17IPS20 PCB can be stuffed to make many PCBA for the required TV model.

[nomoresonys]

Re: Faulty display? Vestel TV

DO both tvs have the same panel number? which should be on the back metal chassis of the tv on a sticker someplace.

[Askic]

Re: Faulty display? Vestel TV

The panel numbers were not the same. Tv with faulty display is model t39fx182dlp and model with no backlight is r39fx182dlbp. I decided to try and moved the complete metal casing with supply unit, MB and LEDs to other TV and everything worked. the first TV had faulty tcon. I have managed to make one working tv out of two, but the picture is rotated 180 degrees. I have found on the Intertnet that many had similar problem. I didn't find the solution because there is no option in service menu to flip the picture. I need to rotate the TV

[yokoono]

Re: Faulty display? Vestel TV

What is the panel code?

[Askic]

Re: Faulty display? Vestel TV

Panel is VES390UNDA-01. When I insert MB 17MB82-1a picture orientation is OK, but picture is low quality and bit fuzzy. With MB 17MB82s everything is OK but picture is upside down. Unfortunately there is no option to rotate puc in service mode. Right now, the TV is rotated so I can normally watch.

[yokoono]

Re: Faulty display? Vestel TV

Below is the PQ profile for the TV panel. Put it on the stick and follow the installation procedure. I think you know her. After that the image will return to normal.

[Askic]

Re: Faulty display? Vestel TV

Ok guys, thanks for the help.
I'll try now to sum up my experience with this problem because it might be helpful for others.

I started with randomly no backlight issue on Telefunken T39FX182DLBP, date of production 1304. After an hour or two after being disconnected from the power supply I could turn on the TV and everything was normal for a few minutes then backlight disappeared while sound was still good. Next attempt to turn OFF/ON resulted in no backlight. I have tested output voltage to the LED and there was short spike in voltage to 185 VDC and then back to 120 VDC. On this forum and on MrReeceyburger123's video on youtube I learned that this could be the most probably symptom of the failed LED. I'm not sure how to explain why it worked sometimes. If one ore more LED's are faulty, then it shouldn't work no matter what.

The TV had 17IPS20 supply board with the following numbers on it: 040313R5 and bar code sticker with number: 23117579-27002042 298 and mainboard 17MB82-1a with number: 10083714 23100546 103 39”, 27001098, MB82(OEM)

While measuring voltages on different parts of the 17IPS20 supply, I caused short circuit on Q211 and it was the end of supply board. Now, there was no standby LED active anymore. I was about to throw the TV to the recycle bin, when I learned that a friend of mine had similar problem but with “faulty display”. On this TV, supply board and backlight LEDs were 100% OK, so I decided to try to combine the parts and make one TV works correctly.

The other TV was model T39FX182DLP with date production 1404. On this TV after turning , part of the picture was light gray. I concluded that most probably on this TV problem is with T-con board (thin very long PCB that has flat cable connection to the motherboard. So I moved complete metal chassis from this TV to the TV that had problem with no backlight. This TV had little different 17IPS20 and MB (and of course t-con). I didn't take picture on this supply board but I know it has R6 (probably revision 6) as additional number and its MB is 17MB82s.

When I installed metal chassis from T39FX182DLP to T39FX182DLBP TV and connect it to original LCD panel, everything worked but the picture was upside down. I have tried to replace 1MB and put it back original one (17MB82-1a), which corrected picture orientation, but quality of picture was bad (fuzzy and almost double), so I installed back the 17MB82s.
I was about to mount the TV upside down on the wall carrier when yokoono provided the solution.

The cause of the picture upside down is a mismatch between the actual LCD panel (t-conv) and the information driver in the MB.
The panel number VES390UNDA-01

I used the following procedure:
1. Format USB drive to FAT32 file system
2.Created on USB drive folder "read" and copied pcf.bin and pqf.bin
3. Put USB drive to USB port in TV
4. Power-on TV
5. For input to the service menu, use the button sequence [ MENU+4+7+2+5 ] on the remote control (Vestel)
6. Find-up item in service menu for USB operations
7. Scroll to item USB operations and push the OK button and followed what was instructed.

After procedure was done, the picture was correctly oriented.

[yokoono]

Re: Faulty display? Vestel TV

1. Format USB drive to FAT32 file system
2.Created on USB drive folder "read" and copied pcf.bin and pqf.bin
3. Put USB drive to USB port in TV
4. Power-on TV
5. For input to the service menu, use the button sequence [ MENU+4+7+2+5 ] on the remote control (Vestel)
6. Find-up item in service menu for USB operations
7. Scroll to item USB operations and push the OK button and followed what was instructed.

This procedure is to copy the profile from the TV by stick. To copy the profile of the panel to the TV, a folder called PQ is created and PCF and PTF are put in the request. Otherwise, proceed as above.
The folder called READ is valid ONLY for 17MB82. For others it is called "downloadprofile.mbXX"
To copy the profile from the stick to the tv the folder is called "profile"

[Askic]

Re: Faulty display? Vestel TV

yokoono,

Can you please elaborate more? We found the procedure on elektroda.pl I'm pretty sure that we didn't create any request folder. I'll need to check this with my friend, since this performed this part.
In this case, information of the panel should be downloaded to the mainboard, since mainboard contains info about the previous panel.

[Davi.p]

Re: Faulty display? Vestel TV

The problem in post 1 is much probably or almost sure oxidation on screen's pcb, almost not fixable..