LG 70UH6350 (UB.BUSMLJr)

[nonsub]

Re: LG 70UH6350 (UB.BUSMLJr)

To be clear... removed U ribbon completely on left side, tested, no diff. Put back on and removed U ribbon from right. Same thing exit standby = 3 flashes. No BL at any point. Button on TV loses function but remote power button still takes in and out of standby.

Also sorry but If I connect HDMI signal it will default select it?

[nonsub]

Re: LG 70UH6350 (UB.BUSMLJr)

To be clear... removed U ribbon completely on left side, tested, no diff. Put back on and removed U ribbon from right. Same thing exit standby = 3 flashes. No BL at any point. Button on TV loses function but remote power button still takes in and out of standby.

Also sorry but If I connect HDMI signal it will default select it?

Yes so connected HDMI to PC. Normally Windows will detect the HDMI audio connection but does not. Does this not prove that motherboard is bad?

[Diah]

Re: LG 70UH6350 (UB.BUSMLJr)

at this case.... disconnect the panel complete from T-CON.. ( disconnect the 4 ribbon from T-CON side.... tv in normal case work with out Panel in place )... and work first on MB.. its suspected. BGA or NVM / SPI./NOR.
3Flash by LG also tell if there are some where short include BL

also you can do it as you wrote at first post... MB disconnected and run the PCB stand alone...
LVDS between MB - T-CON disconnected.... panel connect to T-CON
feed from PCB 12V line direct to the T-CON fuse

turn on and check what you will have on screen... and if the 12V drop down or not

[nonsub]

Re: LG 70UH6350 (UB.BUSMLJr)

Thanks again for all the time trying to help.

at this case.... disconnect the panel complete from T-CON.. ( disconnect the 4 ribbon from T-CON side.... tv in normal case work with out Panel in place )... and work first on MB.. its suspected. BGA or NVM / SPI./NOR.

Yes I believe MB is the problem even if 2 x boards (original + E-pray board.) But I am scared to spend 200 $USD + shipping without knowing for sure

3Flash by LG also tell if there are some where short include BL

OK but I see full backlights when I give 3.5V to DRV_ON so this proves BL is ok?

I also have a cheapo BL tester but I think it would be hard to test on ribbon...

also you can do it as you wrote at first post... MB disconnected and run the PCB stand alone...
LVDS between MB - T-CON disconnected.... panel connect to T-CON
feed from PCB 12V line direct to the T-CON fuse

turn on and check what you will have on screen... and if the 12V drop down or not

When you say PCB I assume you mean the power board? OK so with MB disconnected I must trigger PWR_ON with 3.5V. I take also 12V to fuse on T-CON. Other side of fuse I read ~12V and nothing on display

[Diah]

Re: LG 70UH6350 (UB.BUSMLJr)

1- trigger PWR_ON & DRV_ON with 3.5V. I take also 12V to fuse on T-CON

2-the way you tested and BL come on.... yes you have light can see.. but the protection circuit which monitor and send signal to MB are disabled ( MB disconnected )

[Diah]

Re: LG 70UH6350 (UB.BUSMLJr)

Yes I believe MB is the problem even if 2 x boards (original + E-pray board.) But I am scared to spend 200 $USD + shipping without knowing for sure

then nothing left only Dirty Test
all cable boards / panel connected at it should.
ONLY on power boards socket to MB. clip out from socket only the wire line of DRV_ON, and trick the pin on the socket with 3.5V as you did before... turn on and check what do u have on MB and screen ... measure V on T-CON too.

[nomoresonys]

Re: LG 70UH6350 (UB.BUSMLJr)

well could try another mainboard, maybe get one from a seller that will accept returns if the board doesn't cure the issue.

[nomoresonys]

Re: LG 70UH6350 (UB.BUSMLJr)

are you sure tv is direct lit? sams club says edge, kinda looks too thin to be direct lit.

[nomoresonys]

Re: LG 70UH6350 (UB.BUSMLJr)

did you ever notice what level you were running the backlights on, such as vivid which is full blast, were they turned all the way up to max?

[nomoresonys]

Re: LG 70UH6350 (UB.BUSMLJr)

Thank you. OK I will check this but this is also the second tcon board.

If blacklists go on when manually 3.5v drv and our on they are for sure good or could still be the problem? I ask because I see another thread on this unit that this board will not boot if backlight problem and to cut safety wire to test (but where us safety wire?)

Thx

Is this thread here?

[nonsub]

Re: LG 70UH6350 (UB.BUSMLJr)

are you sure tv is direct lit? sams club says edge, kinda looks too thin to be direct lit.

Yes sorry you must be correct. For some reason I thought local dimming had to be direct of FA.

Looking at your other kind replies... reminds me of one of the (many) youtube vids I checked... in that case it seemed like full brightness was drawing too much and the guys solution was to cut the SAFE (I think called) line and all was good (which does not seem like a good idea lol.) Anyway this PCB doesn't seem to have such a thing. I've never adjusted brightness TBH.

See next post I've a good update!

thanks again!

[nonsub]

Re: LG 70UH6350 (UB.BUSMLJr)

then nothing left only Dirty Test
all cable boards / panel connected at it should.
ONLY on power boards socket to MB. clip out from socket only the wire line of DRV_ON, and trick the pin on the socket with 3.5V as you did before... turn on and check what do u have on MB and screen ... measure V on T-CON too.

I feel like we are getting somewhere now!!!

You know this was a test I did before this but did not jump the 12V to TCON and also it seems to me that I also needed to cut the PWR_ON line. Maybe this is wrong though and I missed a connection.

Anyhow so now we have these results:

Power board to MOBO = cut PWR_ON, DRV_ON, feed 3.5V
Power board to TCON fuse = jump 12V

I get various results from disconnecting different TCON > PANEL ribbons.

I can get half of screen lit white at a time but not both together. It seems like the middle two TCON > PANEL ribbons do this.

No difference if MOBO is completely removed or connected.


So I think we are pretty clear that MOBO is definitely bad?

Are we near 100% that all other components are good or is there more TCON testing to do?

[Diah]

Re: LG 70UH6350 (UB.BUSMLJr)

i think i wrote only DrV_on to take out.. MB Power on signal are fine as i read from yours first post... so why you ignore it!!! bad

and no need to feed T-CON with 12V in this test..

[nomoresonys]

Re: LG 70UH6350 (UB.BUSMLJr)

well I don't know exactly but theres a tcon I think will work if it could be the problem: https://www.tvpartstoday.com/RUNTK56...tk5655tpza.htm

[Diah]

Re: LG 70UH6350 (UB.BUSMLJr)

i am talking not early test... my talking on DIRTY TEST.

[nonsub]

Re: LG 70UH6350 (UB.BUSMLJr)

well I don't know exactly but theres a tcon I think will work if it could be the problem: https://www.tvpartstoday.com/RUNTK56...tk5655tpza.htm

Thanks but this is the second TCON lol.

[nonsub]

Re: LG 70UH6350 (UB.BUSMLJr)

then nothing left only Dirty Test
all cable boards / panel connected at it should.
ONLY on power boards socket to MB. clip out from socket only the wire line of DRV_ON, and trick the pin on the socket with 3.5V as you did before... turn on and check what do u have on MB and screen ... measure V on T-CON too.

OK will do. What do you want me to check on the MB though?

thx

[nomoresonys]

Re: LG 70UH6350 (UB.BUSMLJr)

Thanks but this is the second TCON lol.

ok, after Diahs test, maybe put the other tcon in and see if you get the same results as in post #32, if you haven't tried both tcons for that test yet, interested to see if they both give the same display.

[Diah]

Re: LG 70UH6350 (UB.BUSMLJr)

ok, after Diahs test, maybe put the other tcon in and see if you get the same results as in post #32, if you haven't tried both tcons for that test yet, interested to see if they both give the same display.

his T-CON working... and he will get same result even new t_CON from Factory.... no signal mean half buffer.. line etc. photo 1 photo2

OK will do. What do you want me to check on the MB though?

thx

nothings just do as i wrote before and here again..
every things connected as it should even the panel riboon all in place.
only DRV_ON cable at PCB socket cut it off and feed its pin with yours external 3.5V

check screen and check T-CON if the MB feed it 12V or not...
my way to find the fult at MB to repair it if you can of course....

[nonsub]

Re: LG 70UH6350 (UB.BUSMLJr)

his T-CON working... and he will get same result even new t_CON from Factory.... no signal mean half buffer.. line etc. photo 1 photo2



nothings just do as i wrote before and here again..
every things connected as it should even the panel riboon all in place.
only DRV_ON cable at PCB socket cut it off and feed its pin with yours external 3.5V

check screen and check T-CON if the MB feed it 12V or not...
my way to find the fult at MB to repair it if you can of course....

OK so did exactly as advised:

As usual power button takes out of standby one time but then has no function.

RC power goes in and out of standby as before.

Each standy/exit standby = BL and random lines display/flicker like pics. Also lines "jumping" 11.5V @ TCON