Just picked up a 55 inch LG 4k OLED for $50!

[freakaftr8]

Re: Just picked up a 55 inch LG 4k OLED for $50!

I shloukd have noticed this before but the outer ribbon to that area in question on the panel has a solid burn through a trace on the ribbon. Obviously a short. I swapped cables from the opposite side to hear a subtle ticking sound from the tcon. Most likely the end COF is melted.

[Davi.p]

Re: Just picked up a 55 inch LG 4k OLED for $50!

What do you mean for short? 0v in diode mode? 0ohm?

[Davi.p]

Re: Just picked up a 55 inch LG 4k OLED for $50!

"Most likely the end COF is melted." Don't judge an object that you don't know, i guess you never dismounted a OLED panel, there can be more electronics on that than lcd panels, surely you have to remove that funny "carpet" around the thing.. (i mean that strange white texture )

[Davi.p]

Re: Just picked up a 55 inch LG 4k OLED for $50!

But on the tcon there's a product. date, is 2015 or 2012? Is there any SM?

[freakaftr8]

Re: Just picked up a 55 inch LG 4k OLED for $50!

I will investigate further however I don't know how to pull off this back cover

[freakaftr8]

Re: Just picked up a 55 inch LG 4k OLED for $50!

Ok. Believe it or not I scored a NOS panel from ebay!! Before I replace the panel I am going to check different capacitance readings between the 2 panels and see if I can straighten this 1 out 1st but somehow I managed to find one out of Utah for 300 bucks unbelievable!

[freakaftr8]

Re: Just picked up a 55 inch LG 4k OLED for $50!

Got the panel. The readings on those 4 caps on the panel that were 80 ohms are 250 ohms on this panel. Same as other side. However I still have a mainboard issue.

Nothing while pressing power button. Pressi g power on remote yields a flashing power LED. That's it

Only 3.5v to mainboard. Nothing being sent out.

Can manipulate panel on, power on, and 12v,24v on with resistors. New panel lights up.

No 3.3 to VCC of eeprom. As a matter of fact, no 3.5 or 3.3 missing in a lot of areas.

Nothing on voltage regulators, nothing getting even slightly warm, even after forcing ps_on

[freakaftr8]

Re: Just picked up a 55 inch LG 4k OLED for $50!

Btw I don't get test patterns with LVDS disconnected. Not sure but guess this tcon doesn't support that? Panel came with tcon.

Pretty sure on old panel/tcon it was attempting to initiate test patterns.

[Davi.p]

Re: Just picked up a 55 inch LG 4k OLED for $50!

"New panel lights up" with which image?
"No 3.3 to VCC of eeprom" which eeprom? marking?
"no 3.5 or 3.3 missing in a lot of areas." ???? Are you forgeting a comma?
"Nothing on voltage regulators" Are you meaning only single chip linear or dc-dc switching p.supplies?

[freakaftr8]

Re: Just picked up a 55 inch LG 4k OLED for $50!

When I say new panel lights up it esentially primes where you can see the pixels illuminate with a very dark glow.

[freakaftr8]

Re: Just picked up a 55 inch LG 4k OLED for $50!

There is no VCC to any pens on any of the voltage regulators or Eeproms. Even when I force power supply on I get 12 V and 24 V all over the board but yet nothing going into any of the voltage regulators or eeprom. I have searched all areas of the board for fuses and inductors and they all test good so I'm starting to think that there is something else going on here

[Davi.p]

Re: Just picked up a 55 inch LG 4k OLED for $50!

Is not very useful to test an inductor, i've never found or hear one defective, also testing dc-dc regulators seems not useful 'cause your problem is to start the tv, maybe the standby processor is embedded in the main cpu and uses an external flash spi to run the sw. Check if there's that flash and if is powered, usually it has a paint mark on it. Given that the standby led is lighted, the cpu is working but maybe it needs a special procedure to fault reset or has no good sw on the spi.

[freakaftr8]

Re: Just picked up a 55 inch LG 4k OLED for $50!

That's what I'm figuring it does use an external Flash eeprom. I believe there some reset procedure as the guy I bought it from said it will only turn on so many attemps with a bad panel until it goes into this procedure or mode.

Uses a Macronix M25Q032A. Already tried resetting by ground to reset pin 7. However there is no VCC to the eeprom so efforts are pointless.

[Davi.p]

Re: Just picked up a 55 inch LG 4k OLED for $50!

"Uses a Macronix M25Q032A. Already tried resetting by ground to reset pin 7."
What is this reset?? Are you trying to erase the standby software? Why??

"I believe there some reset procedure as the guy I bought it from said it will only turn on so many attemps with a bad panel until it goes into this procedure or mode. "
Sorry i can't translate...

Anyway aren't you able to follow a bit the path of the 3,5v in input to where it stops?

[freakaftr8]

Re: Just picked up a 55 inch LG 4k OLED for $50!

Yes I followed it in to the main processor and the NV ram modules but nothing coming out to Eeprom

[Moreno83]

Re: Just picked up a 55 inch LG 4k OLED for $50!

Im curious if you can fix this tv. How much did you pay for the panel?

I thought most OLED's fail with either the panel or T-con and not mainboard? No way to download some firmware somewhere?

[freakaftr8]

Re: Just picked up a 55 inch LG 4k OLED for $50!

I paid 330 with shipping. Yes OLED seems to be very problematic as the chip on film ribbons get extremely hot. This one inevitably appears to be a mainboard failure as I can apply resistors to the circuit to power up the 24, 12 V and get the tcon up and running and give me a blank black raster. I did that with the other panel and was presented with a huge vertical stripe on the right side. I have still yet to dismantle that panel however there's a gentleman here in Sacramento that has ATV same model with a cracked screen for $80 that I'm gonna pick up. Maybe get a good main board out of that one and look for the differences between the boards to find out what's wrong with this mainboard.

Even though main board failures seem to be rare and OLED, It's still in LG and LG is infamous for failed BGA on main processor.

[freakaftr8]

Re: Just picked up a 55 inch LG 4k OLED for $50!

I think when I get it all repaired and up and running I'm going to turn around and resell it. I will take LED backlight failures or 1080p plasma over burning OLED panels anyway of the week.

[vinceroger69]

Re: Just picked up a 55 inch LG 4k OLED for $50!

whats the full model number of this set.

[freakaftr8]

Re: Just picked up a 55 inch LG 4k OLED for $50!

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