Samsung ue58tu7100

[thuss]

My mates samsung tv. Symptoms are backlights flash then switch off.

Some times it displays an image which fades. Suspect a bad panel.

Disconnected main board from psu and the backlights stayed on.
Reconnected everything. Then Disconnected the ribbon from main board to panel -backlights stayed on with sound but no image.

I suspect it's the panel and maybe the following chip on the panel. AAT7212 which I've attached a photo of (not very clear).

I've searched for a AAT7212 datasheet but couldn't find one.

In the attached photo leg 3 and leg 8 are reading short highlighted by red lines.

But Im possibly wrong just wondering if anyone has come across this and I would be grateful for any help/advice.

[alfatv]

Re: Samsung ue58tu7100

Leave that chip alone.
Search this forum for un58tu* and un50tu*, panel issue.

[nomoresonys]

Re: Samsung ue58tu7100

start with an easy test, test the little mlc caps on the long thin panel driver boards, check them for shorts or very low ohms.

[thuss]

Re: Samsung ue58tu7100

start with an easy test, test the little mlc caps on the long thin panel driver boards, check them for shorts or very low ohms.

Happy New to all.

Checked all those little caps no apparent short or low ohms.

individually disconneced the two ribbons that attach to the screen . Get pixalation on the screen when one ribbon/tab is removed but when both are attached tv just keeps trying to boot up but no image.

On the main board side the large ribbon(lower side of main board) I've tried putting a little tape between 7 and 12- which results in a the tv staying on with sound but no image but a lot of horizontal lines.


Maybe it's just to far gone?

[thuss]

Re: Samsung ue58tu7100

I've just double checked the panel boards and found two caps which I have highlighted that are charging up with a multimeter. the ones I have come across never do that.

I've tried masking pin 12 to 20 no luck . Then masking pin 13 the screen displayed lines in both directions.

[nomoresonys]

Re: Samsung ue58tu7100

so the other caps nearby are not doing the same?

[nomoresonys]

Re: Samsung ue58tu7100

so what do you have with just one ribbon cable attached, is the red light lit on the optical out port of the mainboard? careful not to let the pins of the disconnected ribbon cable touch the metal chassis or anything.

[thuss]

Re: Samsung ue58tu7100

so what do you have with just one ribbon cable attached, is the red light lit on the optical out port of the mainboard? careful not to let the pins of the disconnected ribbon cable touch the metal chassis or anything.

Hi In regards to your first reply only those two caps but I don't regard them as faulty.


Yes the optical port is on.

[nomoresonys]

Re: Samsung ue58tu7100

just set meter to ohms, if its not auto-ranging meter you may need to play with the range 2000k, 200k, 20k, 2000, etc, what is the ohm reading on those two caps and the others there in that area that are the same physical size?

[thuss]

Re: Samsung ue58tu7100

just set meter to ohms, if its not auto-ranging meter you may need to play with the range 2000k, 200k, 20k, 2000, etc, what is the ohm reading on those two caps and the others there in that area that are the same physical size?

It's a autoranging meter. The caps are reading similar to the others, initially i think I wasnt being careful with the meter probes.

[thuss]

Re: Samsung ue58tu7100

just set meter to ohms, if its not auto-ranging meter you may need to play with the range 2000k, 200k, 20k, 2000, etc, what is the ohm reading on those two caps and the others there in that area that are the same physical size?

Yes it's a autoranging meter. The caps are reading similar to others. I think initially I wasnt being careful with the probes.

[nomoresonys]

Re: Samsung ue58tu7100

ok, they seem alright, now my memory isn't the greatest but I thought I saw someone on youtube doing the tape-cutoff method on a tv with no stand alone tcon and only one ribbon cable like yours has there, maybe try that, see if you can get a good image. I like this guys method he's using here, yes I realize that the one he's working on has 2 cables: https://www.youtube.com/watch?v=pfrRhw7-ZII

[thuss]

Re: Samsung ue58tu7100

ok, they seem alright, now my memory isn't the greatest but I thought I saw someone on youtube doing the tape-cutoff method on a tv with no stand alone tcon and only one ribbon cable like yours has there, maybe try that, see if you can get a good image. I like this guys method he's using here, yes I realize that the one he's working on has 2 cables: https://www.youtube.com/watch?v=pfrRhw7-ZII

Yes I saw that video -will try it again. Thanks for your help