xr-55x90j power issue

[EazyBone]

xr-55x90j was picked up free and there is no standby light at all.

I have checked the PSU and it feeds 12v to main board and correct voltage to the LED driver.
I have forced the backlights on and they work through the PSU.

The main board is supplying .178 to the tcon fuse which shows it as 8a/35v.
I try to hit power and the numbers don't change nor does any light.

Is this safe to assume the main board failed here? Anything I should check.

Also there is a main board for this and 65inch which seems to be cross compatible.. would I need to program it before sticking it in or something? That is, if it's main board issue

[EazyBone]

Re: xr-55x90j power issue

When jumping tcon on the tcon 12vtcon line goes up to 1.4v. the cap shown in pic is only hitting 1.4v also. I would assume that this is not correct. Any direction for me on this?

Main board gets 12v but there is no indicator light either and power button does nothing. Any direction? I'm but lost here

[Diah]

Re: xr-55x90j power issue

unplug the socket on t-con which feed the 12v. then do it a you did before .. main boards disconnected and run psu as stand alone with out MB and t-con see if the 12v of tcon correct or not

[EazyBone]

Re: xr-55x90j power issue

Sorry forgot to put pic, yes will try diah.

TCON AND PSU connected (no main board or BL) voltage 1.4v to tcon12v when jumping

PSU standalone, no tcon connected. TCON 12v line is 2.06volts when jumping

[Diah]

Re: xr-55x90j power issue

Sorry forgot to put pic, yes will try diah.

TCON AND PSU connected (no main board or BL) voltage 1.4v to tcon12v when jumping

PSU standalone, no tcon connected. TCON 12v line is 2.06volts when jumping

so your t-con 12v on psu need to work on

[Diah]

Re: xr-55x90j power issue

BTW,,, you need STB connect to PW.on when you do t-con 12V_on

[EazyBone]

Re: xr-55x90j power issue

Yes I have power on, stby on and tcon on jumpered.

How does this explain no standby light though, odd. As other voltages okay.

I'll do more digging i guess

[Diah]

Re: xr-55x90j power issue

Yes I have power on, stby on and tcon on jumpered.

How does this explain no standby light though, odd.

I'll do more digging i guess

don't bother with LED indicator... its Android.. and the indicator digital can be turn off from tv setting

just follow the t-con12v on cold side

[EazyBone]

Re: xr-55x90j power issue

This is what I get so far. Purple is where all the beeps go on the line. Then I lose it, I don't really know how to trace a line well, anyone know of a informative thing?

There's only one cap along the line that I see which is the one from post 4 first picture.

This is where I'm at

Edit, I just pulled that cap off to test and it's 325uf which is pretty spot on.

[Diah]

Re: xr-55x90j power issue

you have low currents on this line as you wrote 2.06V. its much like you have R changed value and this common issue at PW_ON or T-CON12_ON.. also the other common issue optocoupler.

[EazyBone]

Re: xr-55x90j power issue

Is this the optocoupler you are talking about? Is there a way to test it? Gonna research it

[nomoresonys]

Re: xr-55x90j power issue

Opto is PC6201.

[EazyBone]

Re: xr-55x90j power issue

Long time no see Sony, know of how I can test it? It's this in the picture right?

[Diah]

Re: xr-55x90j power issue

Long time no see Sony, know of how I can test it? It's this in the picture right?

lol..... this is transformer.. the opto the ic with 4 pin close to it down

[Diah]

Re: xr-55x90j power issue

from the mistake above, i suggest you to test the t-con and panel as stand alone if they are fine then buy PSU
you test before BL on and power On which you have 12V to MB ---- use this 12V to test T-con... MB should be disconnected from PSU and T-CON also, t-con 12V socket need to be disconnected too from PSU

note t-con need to have the - too... because u will disconnect the sockt

[EazyBone]

Re: xr-55x90j power issue

I just saw the optocoupler on a video and researching it. He used compress air to freeze it and it started working, just saw what it is now. Thanks.

Okay diah. TCON needs to have - too? What does this mean. It needs grounded is what your saying?

So the PSU supplies 3 12v wires to tcon, do I need to connect each wire to the 12v? But this will happen tonight! Awesome.

Appreciate all the effort you put into these posts diah, thanks.

Others as well.

[lotas]

Re: xr-55x90j power issue

This clearly shows that the problem is with the motherboard.

[Diah]

Re: xr-55x90j power issue

This clearly shows that the problem is with the motherboard.

No Lotas.... the T-CON12V come from PSU not from MB... and when he do PSU stand alone test ...PW_ON are fine 12V to MB exsisit and BL_on also BL tuen on... only T-con12V_on have low voltage 2.6V

I just saw the optocoupler on a video and researching it. He used compress air to freeze it and it started working, just saw what it is now. Thanks.

Okay diah. TCON needs to have - too? What does this mean. It needs grounded is what your saying?

So the PSU supplies 3 12v wires to tcon, do I need to connect each wire to the 12v? But this will happen tonight! Awesome.

Appreciate all the effort you put into these posts diah, thanks.

Others as well.

1- the socket between T-COB and PSu disconnected
2- MB disconnected to PSU and LVDS to T-CON too
3- just do PSU stand alone STB to PW-ON and STB to BL-ON as you did before

the 12V the PSU generated to MB use it to T-CON...if u have Fuse put it on it...
just think we are disconnecting the socket of 12V from T-con and PSU... so the GND chassis line will be disconnected.... so we need to do it in case the t-con have no GND

[lotas]

Re: xr-55x90j power issue

The backlight does not start (there is no command from the motherboard, 12v is not supplied to the T-con, there are no indicators, there is no sound in the speakers... and what could it be?

[Diah]

Re: xr-55x90j power issue

The backlight does not start (there is no command from the motherboard, 12v is not supplied to the T-con, there are no indicators, there is no sound in the speakers... and what could it be?

lotas... are you under drinking.. or mixed with other threat.... read this threat first post lol