Samsung un58tu7000fxza - Power cycles with no picture, only backlight

[cheebster]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

https://www.youtube.com/watch?v=fIYW-Uuun4o

[nomoresonys]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

couldn't understand the dialog, looks like he cut the trace to eliminate the short and left those 3 components off, wonder how many models this can be applied to and suppose it depends on where the short is, unless thats where you cut if theres a short at all??

[nomoresonys]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

so he says remove the 3 IC's first then try it, if no joy cut trace, suppose it only applies if you find a short like he did, so if you find the short is still there, then you cut, I notice its just a very small cut.

[cheebster]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

Yes. But on this set, these ic's don't exist, instead i have very small ic's which i can't identify without the microscope, very tiny.

See picture again, beside each line there's small ic's there. I tried measuring, but didn't go far. Very tiny stuff, waiting for headband microscope to arrive..

[nomoresonys]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

yes, pretty sure its only for specific models.

[nomoresonys]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

that microscope sounds interesting, do you have a link?

[nomoresonys]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

wonder if IC9 is ok, can you see the numbers to bring up a datasheet?

[pdsterns]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

Update: reputable TV shop will not even work on this model, he says it has 20 ways to die. He recommends Sony, LT or Vizio

[nomoresonys]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

cant say hes wrong, samsung I dont trust for quite a while now and lately I dont trust sony either.

[cheebster]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

Ok, so i got the schematics for the panel on this one, it's a panda CC580PV6D.

Here it is. I'm trying to find out, the taping method, it some of the clock lines that they are blocking ?

[cheebster]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

Ok, well ive managed to get this set to turn on.

See this : https://www.badcaps.net/forum/showthread.php?t=107445

Well, it works on that set too. But im missing a bit..

If i remove the VGH on bootup (pin22) than apply it after a few seconds, it works, with a jumper wire going to the testpoint on the panel's pcb, it works, with a few defects on the screen (lines) but it works.

Now to follow up.. From that thread, the OP did a mod where he added a 10k resistor inline. I tried that, got 6.xx volts instead of 25 and it didn't work.

[nomoresonys]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

well I admire your determination, hope you succeed.

[cheebster]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

Ok, so after leaving the set on for a while it powers on without an issue, having everything put back to stock, with the jumper removed.

Is it because the set is hot that it struggles less ?

Anyhow, here's a picture of what it looks like. I don't understand, removing the small U bridge from the left side of the tv was having it not shut down, but the problem seems to be on the right side of the tv, this is where the main flex arrives from the mainboard. I'm confused.

I'm really confused now.

[nomoresonys]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

its usually only one side, do you have a picture of the u bridge, so we can be sure it's the same thing.

[cheebster]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

Yes, it's shown here : https://www.badcaps.net/forum/attach...1&d=1639633179

[nomoresonys]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

I don't see it.

[cheebster]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

Ok, so from the service menu it seems clear that the problem lies on the right side of the pcb, being the left side of the screen.

OP, here's some good videos that show how to fix it, if you want to take the time to do so;

https://www.youtube.com/watch?v=cwxSK4JGMg4
https://www.youtube.com/watch?v=5PPPeFjplIU

Basically, isolating the CK1-8 lines that are problematic

[cheebster]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

Here is what mine does now, idk why it came back to life after messing a lot with it.

Would removing the faulty CKx line off the pcb remove these lines, are they caused by a short in the panel itself ?

I can't tell myself from the current screen.

[cheebster]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

Ok, it doesn't make sense to me.

I found there a way to enable the video with that jumper (shown on pic) on half of the screen even with the U connector to the panel removed.

I still get these lines on the screen, even with the left side of the screen turned off.

So, it means these lines actually come from this side and this is where the issue is ? Im really confused, with all the screen on with the test patterns, i was under the impression that the other side was the culprit.

[nomoresonys]

Re: Samsung un58tu7000fxza - Power cycles with no picture, only backlight

.