Samsung UE50TU8000K Boot loop.

[Donny2derby]

Ok team. Let’s see if the finest minds on Badcaps can deliver the goods yet again.

Done the usual disconnect PSU from main board and get good result for steady backlight. Panel buffer boards seem in good health with a very small impact damage to one of them that could have been caused by me during disassembly. However when powered up the backlights still remain on so I’m confident there has been so significant damage to those buffer ribbon cables.

I’ll go through the MB with a fine tooth comb looking for shorts but what are the suggestions in the mean time?

The first time I powered up before disassembly I did very briefly get a dull screen with the HDMI screen on display before it went into boot loop.

Special shout out to the special forces members of lotas & Diah

[Donny2derby]

To add to this. When I test the small SMD caps in the area of the board around what I believe to be inductors (marked 2R2) I get good, solid readings with caps that begin to discharge very slowly.

And also the same good readings around the Ic VPMS2SM DA2037 SMPF 019, good, steady readings on the caps in that area.

When I move to test the ones in the area of Ic marked TAS5749M 09W G4 CFC6 the multi meter jumps around between micro and nano farad without ever giving an actual value.

However. I’ve read the forum enough now to understand that Samsung is famously bad for firmware failing. Is there a test I can do for this to confirm or should I simply bite the bullet and order a CH341a programmer?

[lotas]

Place a jumper and disconnect the LVDS cable from the motherboard, turn it on and see if it reboots or not, if there are no reboots, then there is a problem in the panel.
This is not a series where the firmware fails; the “TU” series is very famous for having a non-working panel and backlight burnout.

[Donny2derby]

Lotas this is excellent. I will do this immediately. Whilst I prepare the jumper kindly explain the purpose of this test.

Ok lotas interesting. The panel goes into bootloop 2 or 3 times then give a maintained and steady backlight. So does this indicate the screen is ok and we should continue with the fault finding?

I have seen in other threads to check for 12v from Ic1603 Ut to buffer boards. But I’m struggling to find a pinout for the Ic.

Exciting progress though!😀

[Diah]

you said that you saw HDMIL on screen at first time... can we see the panel buffer boards complete.

[Donny2derby]

you said that you saw HDMIL on screen at first time... can we see the panel buffer boards complete.

Yes the very first time I powered on Diah. But I also tried twice more before initial disassembly and it did not go to HDMI screen on those 2 next attempts at power on.

Set is no safely secured away in secrecy at work. The next shift returns soon so I need to tidy away haha. Hopefully I can continue the process tomorrow or if not then most definitely can continue with work on it Saturday night onwards when I am on night shift.

lotas do you think it will be good idea to order CH2341a programmer in mean time in case you recommend software update?

Thanks to you both for help and support as always 👍🏻

[Donny2derby]

lotas Diah

Where do you lads suggest I go with this fault finding now? What is next stage of process? Should I check for 12v from Ic1603? I have noticed that there is a small dot on corner of this Ic, does this indicate where PIN number 1 is?

Kindly advise of next steps to take.

[Donny2derby]

lotas


I’ll be getting this TV out of storage later to continue the repair work on it.

Im going to attempt tape method on it first. Am I best off removing the jumper wire you asked me to install first or not?

Diah I’ll get the picture of the buffer boards up as well. But you’ll probably be tucked up in bed when I do haha.

[lotas]

Hi, show me a photo of the damage to the buffer tapes first, maybe there will be no need for further repairs.

[Donny2derby]

Ok mate.

It’s an hour or so until I will retrieve the set from where it’s being kept.

The damage is only very slight. Almost like a small part of one of the tab has become slightly depressed. I wouldn’t imagine it has actually caused any damage to the panel or image.

[Donny2derby]

Ok mate. Photos of panel tabs below with buffer boards also included.

I hope you can make out the very small amount of damage to the tab I’m referring to.

Should I try tape method? Or do you have a different suggestion?

[Donny2derby]

Ok lotas I decided to jump in and attempt tape method and progress has been made.

With the tape on this part of the board I get the below image.

[Donny2derby]

And now without any tape at all the image appears clearer! This is with the link installed you asked me to a few posts back.

[Donny2derby]

Ok stand down lads.

Cracked screen. And the worst of it is I think I’ve done it!!