LG 86UK6570PUB 3 Red Blinks

[ChattFix]

Hey Everyone, I have an LG 86UK6570PUB that wont turn on. Power light blinks 3 times. Tested voltage from power supply to main board and it is sending the correct voltage. When testing LEDs I have 1st strip at 210v 20mA, 2nd strip goes from 208v 20mA to 214 40mA. I'm assuming the LED strips is the issue. Anyone seen this before or can point me to something else to check?

[EazyBone]

3 red blinks isn't a error code, this happens every time you turn an LG on.

Plug everything back up turn TV on and take a flashlight to the screen to see if there is picture. If yes then likely LEDs (where you are). Based on your test I would say yes the LEDs are bad. Led tester should bring it to a voltage and be steady around .4v on the tester. Since you are fluctuating on one, then likely yes that's the problem. I would change the LEDs. I test with the tester a few times since human error can occur and you may be messing it up when testing..

But make sure you try the flashlight test to make sure picture is totally fine just for assurance purposes.

Change the LEDs likely

[Davi.p]

Which is your led tester type? Are you setting the Amp? Power board name? Trick it to turn on the lights without main b.

[ChattFix]

3 red blinks isn't a error code, this happens every time you turn an LG on.

Plug everything back up turn TV on and take a flashlight to the screen to see if there is picture. If yes then likely LEDs (where you are). Based on your test I would say yes the LEDs are bad. Led tester should bring it to a voltage and be steady around .4v on the tester. Since you are fluctuating on one, then likely yes that's the problem. I would change the LEDs. I test with the tester a few times since human error can occur and you may be messing it up when testing..

But make sure you try the flashlight test to make sure picture is totally fine just for assurance purposes.

Change the LEDs likely

It looks as though the screen is going through multiple different colors or screens. No image appears but it seems like the screen is flashing different colors almost. Here are some pictures as well as the voltage change. It seems like they both do the same thing.

[ChattFix]

Which is your led tester type? Are you setting the Amp? Power board name? Trick it to turn on the lights without main b.

I posted the picture on the previous post. I did try to get the LEDs to turn on without the MB and same issue.

[EazyBone]

Unplug led connector turn on tv, then use led connector on the working led side and try and see actually what's happening. Try and get the led tester fixed so you can move the screen and don't have to hold the probes at the same time. Could be damaged screen.

This is exactly why I said do the flashlight test first in this rare occurrence that's screen is damaged and you don't waste your time. Try and take a picture or video of it unless you already know that it's a damage screen

[Davi.p]

How can be the same symptom without the main board? How do you trick the PB? I think in this strange power connector MS is the new style of BL_ON, so you can take a zener diode around 3v and put it with cathode to MS and anode to gnd, then a 2k2 resistor from 13v to MS then a wire from MS to PWR-ON, check if the lights comes on.. ensure the zener almost and well soldered

[ChattFix]

Unplug led connector turn on tv, then use led connector on the working led side and try and see actually what's happening. Try and get the led tester fixed so you can move the screen and don't have to hold the probes at the same time. Could be damaged screen.

This is exactly why I said do the flashlight test first in this rare occurrence that's screen is damaged and you don't waste your time. Try and take a picture or video of it unless you already know that it's a damage screen

So it looks like its flashing flashing red green blue white black.

[Diah]

RGB Pattern shown on the Screen, you have one of the LVDS contact pins shorted or damage.. inspect them from both side

[Davi.p]

my first suspicion is bad main software..

[EazyBone]

RGB Pattern shown on the Screen, you have one of the LVDS contact pins shorted or damage.. inspect them from both side

This is the answer. Shorted, damaged, or not fully seated properly (was my problem). Diah helped me figure this out B4. At least the screen is good, get a good picture on the screen and then change the backlights after you get normal picture

[Davi.p]

Don't hope of a simple fix, it can't be a matter of cables, here the tcon is part of the main board, a bad connection would provoke no video at all mostly..

[ChattFix]

Diah EazyBone here is a video of the screen with the test on one side of the leds. Going to reset the LVDS then check all the points I can.

[ChattFix]

Don't hope of a simple fix, it can't be a matter of cables, here the tcon is part of the main board, a bad connection would provoke no video at all mostly..

Are you thinking I need to reprogram the main IC?

[Davi.p]

No the main ic is a microprocessor, the main software is contained usually in an emmc, but good if you make the backlight trick before, even if i haven't ever read about LG with protection mode for faulty backlight.. bad software issue can easily be mismatched with bga issues, and LG is the king of bga issues, serial port debug can reveal some more..

[ChattFix]

Davi.p I have the FT232RL that I use to read error codes through UART, can I use this to connect the RX and TX? If so, what program do I use to grab the codes?

[Davi.p]

usually is very easy to locate serial port on a main board, 4 pin connector, usually not populated, one pin clearly on gnd plane, a side 5v output (not used if not needed), central TX,RX, use a random serial terminal sw, hyperteminal, etc..

[Davi.p]

basically, if you find a log error, example a file not found, error in file, and partition failed to mount, always same error, then software error and stop, if the errors vaires , then failing BGA...

[Diah]

Diah EazyBone here is a video of the screen with the test on one side of the leds. Going to reset the LVDS then check all the points I can.

Dont Touch the Mainboards... there are wrong info written from one user.. this set. are ONE SoC. there are no T-CON on MB... it had separted T-CON.. LVDS damage make the panel in test pattern.
show me the 2 LVDS contact Pins from both side.. don't trust your glasses..

if some one never had this set under his hand should keep silent

[Diah]

Don't hope of a simple fix, it can't be a matter of cables, here the tcon is part of the main board, a bad connection would provoke no video at all mostly..

stop harming other user Sets.... where are the T-CON !!!