LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

[Panczis]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

The error seems to be still on the LCD panel driver, so I think that without removing the source of the protection mode from it, the display will not show anything. With the laptop I can see that the monitor is recognized, the resolution can be change, the refresh rate too, but it makes no difference on the screen. It is disabled, and after all the resets that I tried, at the next startup the error signal is being send again. The only moment that shows something on the screen is the LG logo on startup, than a horiontal line and in the end the backlight on with an empty black screen

[Panczis]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

Yes, the remote acts now the same as before. But there is still no display on the screen after the logo, nomatter I try to do. Before it was the same, with the buttons pressing on the remote, the red diode acts with a blink. I can always power on/off, the same like before
INSTOP worked as you said. After the code, TV went to standby mode. Then I tried to power it on, and nothing changed.

[Diah]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

use the second main boards and first things try the setting i described before

[Diah]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

one things more.. very important.

you have socket between the main boards and the T-CON which it provide 12V to the T-CON and receive any SOS signal from panel or T-CON.

after the logo and the line appear then screen went to black ..did you still have 12V on the T-CON fuse ?

i just wounder if you unplug this socket did the mainboards turn on and remain on.. you can notice that from the optic output led indicator if its lid red.. if yes remain on... they we can test the panel and t-con by just feed the F1 fuse on t-con with 12V line.

[Panczis]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

The second set works almost the same. The only difference is in the LED signals. With the original one, the LED flashes 7 times, with the boards from the TV it flashes only three times. But there is still only logo, the mosue trick doesn not work, the INSTOP too.
After disconnecting the power cords from mainboard to t-con the mainboard stays ON. The SPDIF connector lights on red.

It doesn't matter if t-con is connected or disconnected from mainboard there is still 13V.

I will try to run the panel in the test mode but could you point me where the F1 fuse is located? Is it the fuse near the power connector? Should I disconnect the signal ribbons or the power cords, and just connect the 12V DC to this fuse to run the panel test?

[Panczis]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

I just checked this F1 fuse, near the power plug on TCON. There is 13V still connected to it. It is directly connected with the power plug socket. There are 5 pins in the socket, first three are feeded with 13V, and the next two pins seems to be a ground
What should I supposed to do? Should I disconnect the power plug, and feed the F1 fuse only with 12V?

[Diah]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

I just checked this F1 fuse, near the power plug on TCON. There is 13V still connected to it. It is directly connected with the power plug socket. There are 5 pins in the socket, first three are feeded with 13V, and the next two pins seems to be a ground
What should I supposed to do? Should I disconnect the power plug, and feed the F1 fuse only with 12V?

if you unplug this sockets did you still have 13V on T-CON as you wrote before ???

if there NO any V on t-con after unplugged this 5 pins socket... then disconnect the 2 LVDS and just feed the T_CON with 12V. to run stand alone.... but i am not sure what we will got on the screen ... just try

[Panczis]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

It's missunderstanding. If the 5-ping power socket is disconnected, there is no voltage on t-con, but it is still on the mainboard side

I will try to align with your last hint and we will see what will happen.

[Panczis]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

After disconnecting the LVDS plugs I got something like this:
https://photos.app.goo.gl/67RfTYEWNcDM6kSZ6

The screen is white at the start, and then the LCD seems to be disabled and the picture vanishing to the black

This horizontal line is in the same place, like when the LG logo appears on the startup, but now the colors are in negative.
When the third ribbon (from tcon to panel) is disconnected, than this line is not visible and the scree stays half white. I can record a video too if you want?

[Diah]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

After disconnecting the LVDS plugs I got something like this:
https://photos.app.goo.gl/67RfTYEWNcDM6kSZ6

you have another t-con right ??? if yes try it same way

[Panczis]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

This situation is on the new mainbord and TCON (the second set from a broken TV). I changed them. Before it was the same. All your hints were tested with both sets.

[Diah]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

This situation is on the new mainbord and TCON (the second set from a broken TV). I changed them. Before it was the same. All your hints were tested with both sets.

then we back to yours POST #11 .. you need to check all ceramic caps resistance.. the issue you showed its much like discharge issue at the panel this belong to caps.. hard work but you need to invest time on it.. starting from the side you have the line.. also if left side and right side some component same place and value. you can compare.. one things last.. to be successful by trace let the panel disconnected from the T-CON complete.. let us know the result of yours coming hard work.. good luck.

[Diah]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

i watched the video again and can see the horizontal line on the top very wide and clear.. my questions to you... at time you disassembly the screen did you have along the side edge ribbon with cof on left and right side ???

[Panczis]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

No, there are no ribbons on the left/right side of the screen. All ribbons are at the bottom. There are 4 driver boards connected in a 2 pairs. To each pair there are two ribbons which goes from the TCON board.
This line on the screen is visible only when the third driver is connected. After a few power on actions, this line is not even visible with all the drivers connected, during the logo shows up. The screen unloads itself only with this 3rd board connected. Without it, it stays white, and the horizontal line is not visible
So I suppose that it will be a problem somewhere on this third IC driver. I will measure the capacitors next week. Those drivers boards are symetrical, so it should be possible to find the bad component by a comparision

[Diah]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

No, there are no ribbons on the left/right side of the screen. All ribbons are at the bottom. There are 4 driver boards connected in a 2 pairs. To each pair there are two ribbons which goes from the TCON board.
This line on the screen is visible only when the third driver is connected. After a few power on actions, this line is not even visible with all the drivers connected, during the logo shows up. The screen unloads itself only with this 3rd board connected. Without it, it stays white, and the horizontal line is not visible
So I suppose that it will be a problem somewhere on this third IC driver. I will measure the capacitors next week. Those drivers boards are symetrical, so it should be possible to find the bad component by a comparision

yours panel nothings special at it... it could find at other lg tvs...
the second broken set, is there way for you to test both t-cons you have on it... if it give sign on menu or input ???

[Panczis]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

I already tried both sets, and mixed the TCONs between them, but the results is always the same. The screen disable itselfs after a LG logo, there is no menu, no other screen too. But it seems that both TCONs are accepted by both boards, so the boards and TCONs probably are fine. I have even tried with a third mainboard from the same monitor type, but the result was the same

[Diah]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

did you took a look on yours monitor RC ? how it had function monitor ON OFF,, beside main power ??
i encourage you to install SmartRemote.apk and choice TV ---LG write your model 86ul3e and choice the most model option.. beside the key platter the page and you will find all what you can use to turn on.

[budwich]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

I already tried both sets, and mixed the TCONs between them, but the results is always the same. The screen disable itselfs after a LG logo, there is no menu, no other screen too. But it seems that both TCONs are accepted by both boards, so the boards and TCONs probably are fine. I have even tried with a third mainboard from the same monitor type, but the result was the same

you could try doing a slightly different "cable disconnection" test which might help isolate the bad side of the panel without impacting as much drivers so that perhaps the shutdown is not activated.
Basically, look along the bottom of the set at the edge boards. On each half of the bottom, there is likely two edge boards which are interconnected with a "U" type cable that is unclampable. Unclamp / disconnect the "U" cable. Leave all the tcon to panel cables connected. See if the set starts up differently. Do the same test again with the other side to see if there is anything different. IF you are lucky, you might get the set past protection. Go from there.

[Diah]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

budwich

i asked him to show us the panel edge boards and he add photos at his post #11 no any U ribbon to see

[budwich]

Re: LG 86ul3e-t logo blinks and then nothing (but backlight stays on)

yes but those pictures are only focused on the board to panel cables and don't show the entire board.