Yet another Samsung bootloop - QE50Q60T

[Davi.p]

My update is that i went to retire the replacement part, that was a spare main board but post service combined a jam and the packet is somewhere in a mistery location, i'm really getting tired of waiting so i discuss here and not in a thread of mine the question, plus in the meantime i reflected and changed my theory a bit, once i was of the opinion like any tech person in the world of a short circuit in gate cof/cog in the panel, until some weeks ago, then i put hands on a recent Qled Samsung, i studied and thinked a bit, i formulated a new theory, bad bga balls on main processor, for the explanation i wait to open my own thread.. so i tried a reflow, not well executed but image appeared! It was with very few lines respect that with the piece of tape trick, so the culprit is definitely oxydation, but i changed my thought, oxydation is general/sistemic not only processor, also panel tab bonds has a slight one.. for the rest, see you next on you tv screens..

Note: also a good reflow will be not enough to be a perfect, lasting fix, to be warned..

[Takeatry]

I removed the heat sink from the main board. The main processor chip got over 200deg F. In less than a minute. I don’t have the tools or expertise to change or reflow the BGA. Guessing I’ll try a new board.

[Davi.p]

Get a board.declared new or 100% guaranteed work or grabbed from a cracked panel

[Diah]

I removed the heat sink from the main board. The main processor chip got over 200deg F. In less than a minute. I don’t have the tools or expertise to change or reflow the BGA. Guessing I’ll try a new board.

this is ONE SoC circuit with GPU .. short at panel will make the SoC hot,,, no shit BGA ...

[Takeatry]

Would I be reading higher voltage somewhere? The most I get at the panel is 20mV.

[Diah]

Would I be reading higher voltage somewhere? The most I get at the panel is 20mV.

man... don't waste money on it you are not the first one.. no one succeed with MB because of the shit rubbish panel.... the other one who complain... give up with words BGA .. do it on your own TVs don't let other user victims of wasting money. you can complain this too ,,

[Diah]

you have reboot.... this mean the boot loader didn't complete its step because of protection signal .. so the SW switch over main boards didn't start to order SoC give permission to DC to DC switched ON to produce the needed V so you have the low 20mV.

on other hand as i wrote before.-.. this is ONE SoC circuit

[Takeatry]

And this is because of the short or shorts on the panel

[Diah]

And this is because of the short or shorts on the panel

yes
lotas can quid you to terminated the main boards to shut down / reboot , so you will see the SoC never being hot..... and with out this you have on the panel buffer boards 2 Uribbon disconnect both... at time no reboot you can check we have several threats on this QLED with one LVDS cable

[lotas]

Would I be reading higher voltage somewhere? The most I get at the panel is 20mV.

T-CON will not output voltage to the panel if the panel is damaged (has low resistance on the supply lines), the protection is triggered and if the LVDS cables are disconnected, then there will also be no output voltage, since T-CON does not see the panel, install a jumper and disconnect U - a shaped cable connecting the non-working half of the panel, and you should have voltage supplying the panel.

[Takeatry]

I been looking at the threads for a few months and have learned at lot. I think I understand the last post. I removed the lvds cable and turn the unit back on. Guessing with the cable removed the signal to try and restart is not there so the SoC won’t keep trying to start and heat up. I tried it and the temp went up to 175F but not further. I would assume this is a clear indication of the shorts in the panel are the problem. I have been using the tape method and trying to check capacitors and clock signals for many weeks. I did not want to give up because the tv at times started and worked. Once for 4 days in row. The 4th day i took off the work area and watched until late that night. Next morning back to the loop. Any other things to try before I give up?

[Diah]

so you did what lotas told you before ..... and it work for few days... this is good but with masking ?
if many time LVDS are in & out 99% the contact pins get broken shorted..

[lotas]

On these latest models, the 4K processors (SoCs) run hot and hot, and not because the panel is faulty.

[Diah]

On these latest models, the 4K processors (SoCs) run hot and hot, and not because the panel is faulty.

NO. they are all in range with heat sink.

[lotas]

NO. they are all in range with heat sink.

It’s already clear that you need a radiator if the processor gets hot, it was installed (the radiator) for a reason.

[Davi.p]

Don't say bad panel until you don't proof it isn't other, if you don't have the means of proof otherwise. be patient, my lost main board packet maybe jumps out one day or another

[Takeatry]

A week or so ago the tv came in 2 days in row with no masking but the jumper wire attached. I kind of jumped into an active thread to ask if the jumper wire could remain or needed to be removed. Diah responded that the wire was for diagnostic only, so I removed it. Not long after that was the period where the tv came in 4 days in row, with no wire and no masking.. Today I checked the cables as best I could for damage, both the lvds and the jumper between the panels. Could not see anything. I reattached the jumper wire and removed the ribbon from the right panel. No difference just the same 20mV. Tried the left side also, no luck

[Diah]

A week or so ago the tv came in 2 days in row with no masking but the jumper wire attached. I kind of jumped into an active thread to ask if the jumper wire could remain or needed to be removed. Diah responded that the wire was for diagnostic only, so I removed it. Not long after that was the period where the tv came in 4 days in row, with no wire and no masking.. Today I checked the cables as best I could for damage, both the lvds and the jumper between the panels. Could not see anything. I reattached the jumper wire and removed the ribbon from the right panel. No difference just the same 20mV. Tried the left side also, no luck

yours main issue was reboot loop, this is 100% Panel and you narrowed down the problem to the right side panel looking from the back of the tv.,,, now as you leaved the jumper long time you could added fault to MB.. no more or lees,, no wasting money and never buy samsung again

[lotas]

The jumper will not harm the motherboard! It only simulates the connection of the panel to the motherboard, but if something is short-circuited on the panel or on the motherboard during diagnostics, then it is quite likely...

Make a high-quality, high-resolution image of this area.

[Takeatry]

Let me know if this is clear enough