Samsung UE55MU6120K Boot loop with backlight no video

[Davi.p]

Re: Samsung UE55MU6120K Boot loop with backlight no video

yes, it seem the correct T-RDY3 point is the one marked by Lotas, not so easy to understand..
Don't expect it will work for long time.. something wrong may exist too..
Let us to know how it goes, i'm much curious..

[fanaticgames]

Re: Samsung UE55MU6120K Boot loop with backlight no video

You didn't seem to put a jumper there.

according to your photo then I made the bridge between pwm4 and rdy1, how can it be that it works now? it's still on without the jumper

Update

take some current photos with the TV on, the temperatures seem perfect both on the motherboard and on the flats of the right and left panel cards which are usually always hot

[fanaticgames]

Re: Samsung UE55MU6120K Boot loop with backlight no video

yes, it seem the correct T-RDY3 point is the one marked by Lotas, not so easy to understand..
Don't expect it will work for long time.. something wrong may exist too..
Let us to know how it goes, i'm much curious..

it certainly won't last for now it's been on for 30 minutes, maybe I'm talking bullshit could it be that some component "discharged" during these days of inactivity? the esd diodes??

[Davi.p]

Re: Samsung UE55MU6120K Boot loop with backlight no video

no, nothing discharged, pwm4 might be the signal that goes to the power board and is for brightness level setting, T-RDY1 might be a fixed 3v i guess, putting pwm4 set to steady 3v could have set brightness of part of the backlights bars to full brightness.. nothing to do with lcd panel i think.. those 2 mosfets are probably final switching transistors for the pwm signals

[fanaticgames]

Re: Samsung UE55MU6120K Boot loop with backlight no video

no, nothing discharged, pwm4 might be the signal that goes to the power board and is for brightness level setting, T-RDY1 might be a fixed 3v i guess, putting pwm4 set to steady 3v could have set brightness of part of the backlights bars to full brightness.. nothing to do with lcd panel i think.. those 2 mosfets are probably final switching transistors for the pwm signals

but the jumper was held for 4/5 minutes with the TV on, now there is no jumper, I also turned it off for 5 minutes and turned it on again and it works regularly

I also redid this wrong jumper last time

[Davi.p]

Re: Samsung UE55MU6120K Boot loop with backlight no video

As obvious i don't know what happened, no schematics, no answers, i have a doubt but i let it stay in silence.. we will see

[fanaticgames]

Re: Samsung UE55MU6120K Boot loop with backlight no video

As obvious i don't know what happened, no schematics, no answers, i have a doubt but i let it stay in silence.. we will see

out of curiosity I disconnected all the flats and reconnected (just to rule out a false contact) and I mounted the cover behind, it still works. Now I'm going to leave a movie playing, let's see...

[fanaticgames]

Re: Samsung UE55MU6120K Boot loop with backlight no video

has been on more than 10 hours without problems, I don't know what to say but it works

[Davi.p]

Re: Samsung UE55MU6120K Boot loop with backlight no video

i am developing from also other threads an idea that the main board stores in an eprom something like an error flag, the forcing of the tcon outputs can restore a visualization and reset that flag, maybe in certain cases the error flag is set due to a temporary malfunction, i'm following another interesting thread, if i have some news i'll let you inform..

[fanaticgames]

Re: Samsung UE55MU6120K Boot loop with backlight no video

i am developing from also other threads an idea that the main board stores in an eprom something like an error flag, the forcing of the tcon outputs can restore a visualization and reset that flag, maybe in certain cases the error flag is set due to a temporary malfunction, i'm following another interesting thread, if i have some news i'll let you inform..

which of the two eeprom? because I made a backup before doing other tests (I wanted to understand if it had a damaged firmware), I could do a new dump and compare if there are differences

[lotas]

Re: Samsung UE55MU6120K Boot loop with backlight no video

25Q80 is responsible for T-Con.

[Davi.p]

Re: Samsung UE55MU6120K Boot loop with backlight no video

No, i think the more possible responsible is the main settings eprom, that is the 24c series eprom

[fanaticgames]

Re: Samsung UE55MU6120K Boot loop with backlight no video

No, i think the more possible responsible is the main settings eprom, that is the 24c series eprom

I have a backup of this before making the attempts I've made

[Davi.p]

Re: Samsung UE55MU6120K Boot loop with backlight no video

and the comparation what says?

[fanaticgames]

Re: Samsung UE55MU6120K Boot loop with backlight no video

and the comparation what says?

identical dumps, no difference

[Davi.p]

Re: Samsung UE55MU6120K Boot loop with backlight no video

comparison not comparation sorry..

[fanaticgames]

Re: Samsung UE55MU6120K Boot loop with backlight no video

bad news, the tv was installed on the wall in its old place with only the power cable and tv antenna connected, the first time it was turned on the error again ... it has been turned on 4:5 days lately without problems

[nomoresonys]

Re: Samsung UE55MU6120K Boot loop with backlight no video

almost seems like something on the mainboard is just getting too hot once you get the back on and it back on the wall.

[nomoresonys]

Re: Samsung UE55MU6120K Boot loop with backlight no video

my buddy tampatec fixed one by putting some good heatsinks on every chip that got pretty warm on the mainboard, might not do the trick but something pretty easy to try.

[fanaticgames]

Re: Samsung UE55MU6120K Boot loop with backlight no video

almost seems like something on the mainboard is just getting too hot once you get the back on and it back on the wall.

impossible has worked with the backcover for over 30 total hours