Tv Samsung qe65q800at not power on

[Michele Romano]

Hello this tv samsung qe65q800at, stuck in stand by if press power led blink but not power at all no light no sound. If disconnettere the mainboard the retr display light is ok . I have also disconnettere the panel , t con etc but notilhing
i have notice that also in standby i have 12,7 volt from psu and not 7.5 where is market on psu main....

[Davi.p]

Maybe bad memory inside main board spi flash ic.. needs reprogramming, otherwise is the same old bad bga balls under one of the chips..
make ritual check on the dc dc step down / main board.. no need of schematics if you know things.. bye.. (where are you from?)

[Michele Romano]

Salerno Italy. Thanks.

[Michele Romano]

I see that the cpu is hot also in stand by... maybe short.....

[Davi.p]

Needs reballing, my bet..

[lotas]

Needs reballing, my bet..

Post removed by admin due to tone of the reply. User disagrees with reballing.

[Diah]

removed

Post removed by admin - user can disagree with post but not bully.

[Davi.p]

removed due to edits above. please everyone just keep it polite. You are allowed to disagree with someone technical analysis but just say so without snarky comments which I see as bullying

[Davi.p]

I see that the cpu is hot also in stand by... maybe short.....

Do you know the story of TV? If TV broken suddenly after bad weather it could be also shorted CPU via HDMI ports.. keep informations about tv..
anyway better to replace board..

[Diah]

What i want to know is if you are really interested or just searching the fight like the bad element under..
.

Hey no bad element over here... we are all human and could do mistake.... but technical forum not only badcaps-net, there are many older than this.we are member at them... . and the admin are high level with technician know how too.. so any one low level will fly out soon after 3 warning if he /she post nonsense diagnose or method

users over here are not technician one, they will believe anx things written over here... so if we are all a ware of not harm such user... we should clear to them the way by explanation to do some things they never did in their´r life.... technicolor who seek help here or own shop he knew where to ask.. just because the nonsense answers given over here..

when we will but end to this theater.. .. no one fighting with you.... we are against your brains.

[Davi.p]

..

[Michele Romano]

I know that tv while are power on shut off and restart after remove the ac alimentation for 5 minutes. This for two times after nothing only red led on that flash if press remote or local button

[Davi.p]

OK so this appears to me as the same common fault of these very very poor designed QLED Samsung (of the series "Once upon a time there was the glorious Samsung.. now down to the sewers!"), thus bad soldering under the processor, here it is worse than other "fresh" faults.. if you stay tuned here, i'm trying to buy another board for mine, the first i ordered is returned back due to a criminal behavior of a postman.. we are in Italy! :-((

[Diah]

I know that tv while are power on shut off and restart after remove the ac alimentation for 5 minutes. This for two times after nothing only red led on that flash if press remote or local button

Q800 had separated T-CON, unplug all 4 ribbon cable between T-CON and panel. try turn on... if remain on.... then try half screen test.
on other hand you have on the t_CON between the 2 LVDS socket 2 point FB1 FB3 this can jumper them in case the first test was OK

[Davi.p]

Post please an overview of back of tv with boards

[Davi.p]

well if tcon separated i don't think or remember Samsung sets falls into protection due to bad screen/tcon, plus the hot cpu makes me think also the already said last suspicion, to get a new board, keep in mind it have to be new or got from working set w/cracked panel.. bye..

[Michele Romano]

It s CPU soldering after reflow start ok.

[Davi.p]

ok thanks for the reply, keep in mind that reflow is not a real repair, the cpu will return to fail, to keep it going farther you can take an hot glue gun and carefully seal all around the border every BGA chip, but reballing and glue sealing is the best for me.. bye..

[Storyteller12]

ok thanks for the reply, keep in mind that reflow is not a real repair, the cpu will return to fail, to keep it going farther you can take an hot glue gun and carefully seal all around the border every BGA chip, but reballing and glue sealing is the best for me.. bye..

Never heard of using hot glue around BGA chips. How does that help? Seems like it would cause more problems as the chip wouldn't get any air flow and dissipate the heat. Which seems to be the reason these chips fail in the first place.

Seems like a proper reballing with lead solder would be enough

[Davi.p]

The sealing would prevent oxidation that it is the cause for me of the chip overheating/detaching..