LG 55EC930V OLED - swich on swich of no screen
My Oled Tv is 55inch tv, 3 days ago I notice that middle of the screen is getting warmer and on picture I have ghosting, missing red color. Color red was still displaying, but it was not so strong as corners of the screen and watching some movies makes me angry.
Then I get an idea to take it apart and clean boards from dust.
In side of Tv was not so bad, I take compressed air in can, and gently blow up.
Also I was thinking to styrofoam sponge to isolate power board from screen that the middle of the screen will not worm so much. Because Led on screen when gets higher temperature, its working resistance gets change, and that could affect difference on displaying red color.
Broads I put back, screwed it, aaaand connect to power wall socket... I try turn on and I noticed it not happened nothing, I check back of tv why didnt turn on, and I noticed that I forget connect power cables to the boards... Ohhh... On cable connected to power wall I take cables from power board and connect first to main board, and then second one to T-CON board. I check one more time all cables if they was properly connected, and I try turn on TV.
And with my surprise, I get white line on top of screen, and then black. Like Tv did shut down. I was so upset
of what did happened. I start thinking what I did wrong that I broke my tv. At first first thought i think that it was spike of voltage from power board to main board when I was connecting power to boards...
Now from reading posts on this site, watching Youtube... A lot of Youtube... After making bunch of testing and voltage reading, I find out that Voltage spike is not so possible, because when power board dont get signal to turn on, he don't provide 12 and 24V to main board. is 0V, only stand by voltage is existing. And I start looking for other possibilities.
Yes, I disconnected all boards from power board, and I check voltages on standby mode.
All was ok. Then Like on another forum was mentioned, I bay pas function of turn on, I put 1Kohm to PWR_ON and DRV_ON, and I check voltages, And looks good.
23.8V, 11,6V, and for TCON 24V+-. Then First assumption is that Power board works good.
Then I go to main board. I connected it to power board, and I try usb wih mp4 movie on second usb input, some peoples said that sometimes helps start board, or just to hear sound if board is working. problem is that my usb stick have led indication if is readed from, and that light was not showing up.
Then I try use one of push buttons on the board to turn on. After doing that steps and hearing 3 times on of, it starts. Power to board with voltages 12V and 24V was correct, no noticed any voltage drop. But Usb did just fast blink, and that's all... Nothing more.
I connected also pc on HDMI port, where alwas was connected, On this port before I brake it, Tv was working on. Also nothing. No sound.
I try another Idea about hard turn on, and disconnect from power wall, but I think this don't have sense, because board have big capacitors, and I noticed that board is going to turn of state when he noticed that power go out. And they are storing enough voltage to sustain stand by mode for a while. Anyway, I try it few times, and didn't help, also when I connected back TCON.
Then I focused on Tcon board. I check voltages on turning on state. there voltage rise to almost 24V and turns of... First My assumption was, maybe there is shortage on board on TCON Board? I check board visually and nothing, I check resistance with multi-meter on side where 24V is supplied, also nothing. Then I get Idea to bypass turn on power board with 1Kohm. I disconnected main board and I put resistors in to socked. I check voltage on TCON, and ..... There was nice steady 24V. I keep that for a while to check if some elements are heating on... Nothing, board was cold.
That Means that power supply for led screen is good.
Then I found out where is fuse on TCON, And I check that, fuse also is good. There gows 12V and is steady. " I want mention that this model OLED have separate power to processor on TCON and separate power going to screen. Means that TCON stripe don't power screen it self, is powering only processor...
Ps, I forget mention that Main board have led indicator which check if TCON send signal if is working or not, and That led is shining on red. I trace that led connection and one of the traces go straight to TCON board. Normally transistor is powered from main board with something 2.3V, But connection from TCON is shortening to ground, and this way, main board knows what is going. Question is if that signal , that red light is good sign or not?
-I still could not figure out which board is broken. Or there are two ones bad?
-Also I dont know if main board can work alone without connecting TCON in this model.
When I try start on with remote or button from Tv on cold board, the screen is dark, but when I turn main board on push button on board, main board processor is warming on, also TCON processor, is warming. And then with remote I turn of and try turn on, I get white strip on top of screen. When Board cools down, white strip is not displaying any more. This strip looks like it treys draw lines 2 times.
In the dark room before I try disconnect main board strip from TCON and this way power on, I see little light on whole screen, but after one second tv turn of...
Last thing what it can come to my mind is If processor on main board have cold or broken connections? And need re solder?? <- this I scared the most.
I did already order new boards for main board and TCON, But when i wait for board to arrive, Stil I am fighting with that problem.
Ps, I dont have old phone to be able do service remote...
Please HELP
Then I get an idea to take it apart and clean boards from dust.
In side of Tv was not so bad, I take compressed air in can, and gently blow up.
Also I was thinking to styrofoam sponge to isolate power board from screen that the middle of the screen will not worm so much. Because Led on screen when gets higher temperature, its working resistance gets change, and that could affect difference on displaying red color.
Broads I put back, screwed it, aaaand connect to power wall socket... I try turn on and I noticed it not happened nothing, I check back of tv why didnt turn on, and I noticed that I forget connect power cables to the boards... Ohhh... On cable connected to power wall I take cables from power board and connect first to main board, and then second one to T-CON board. I check one more time all cables if they was properly connected, and I try turn on TV.
And with my surprise, I get white line on top of screen, and then black. Like Tv did shut down. I was so upset
of what did happened. I start thinking what I did wrong that I broke my tv. At first first thought i think that it was spike of voltage from power board to main board when I was connecting power to boards...Now from reading posts on this site, watching Youtube... A lot of Youtube... After making bunch of testing and voltage reading, I find out that Voltage spike is not so possible, because when power board dont get signal to turn on, he don't provide 12 and 24V to main board. is 0V, only stand by voltage is existing. And I start looking for other possibilities.
Yes, I disconnected all boards from power board, and I check voltages on standby mode.
All was ok. Then Like on another forum was mentioned, I bay pas function of turn on, I put 1Kohm to PWR_ON and DRV_ON, and I check voltages, And looks good.
23.8V, 11,6V, and for TCON 24V+-. Then First assumption is that Power board works good.
Then I go to main board. I connected it to power board, and I try usb wih mp4 movie on second usb input, some peoples said that sometimes helps start board, or just to hear sound if board is working. problem is that my usb stick have led indication if is readed from, and that light was not showing up.
Then I try use one of push buttons on the board to turn on. After doing that steps and hearing 3 times on of, it starts. Power to board with voltages 12V and 24V was correct, no noticed any voltage drop. But Usb did just fast blink, and that's all... Nothing more.
I connected also pc on HDMI port, where alwas was connected, On this port before I brake it, Tv was working on. Also nothing. No sound.
I try another Idea about hard turn on, and disconnect from power wall, but I think this don't have sense, because board have big capacitors, and I noticed that board is going to turn of state when he noticed that power go out. And they are storing enough voltage to sustain stand by mode for a while. Anyway, I try it few times, and didn't help, also when I connected back TCON.
Then I focused on Tcon board. I check voltages on turning on state. there voltage rise to almost 24V and turns of... First My assumption was, maybe there is shortage on board on TCON Board? I check board visually and nothing, I check resistance with multi-meter on side where 24V is supplied, also nothing. Then I get Idea to bypass turn on power board with 1Kohm. I disconnected main board and I put resistors in to socked. I check voltage on TCON, and ..... There was nice steady 24V. I keep that for a while to check if some elements are heating on... Nothing, board was cold.
That Means that power supply for led screen is good.
Then I found out where is fuse on TCON, And I check that, fuse also is good. There gows 12V and is steady. " I want mention that this model OLED have separate power to processor on TCON and separate power going to screen. Means that TCON stripe don't power screen it self, is powering only processor...
Ps, I forget mention that Main board have led indicator which check if TCON send signal if is working or not, and That led is shining on red. I trace that led connection and one of the traces go straight to TCON board. Normally transistor is powered from main board with something 2.3V, But connection from TCON is shortening to ground, and this way, main board knows what is going. Question is if that signal , that red light is good sign or not?
-I still could not figure out which board is broken. Or there are two ones bad?
-Also I dont know if main board can work alone without connecting TCON in this model.
When I try start on with remote or button from Tv on cold board, the screen is dark, but when I turn main board on push button on board, main board processor is warming on, also TCON processor, is warming. And then with remote I turn of and try turn on, I get white strip on top of screen. When Board cools down, white strip is not displaying any more. This strip looks like it treys draw lines 2 times.
In the dark room before I try disconnect main board strip from TCON and this way power on, I see little light on whole screen, but after one second tv turn of...
Last thing what it can come to my mind is If processor on main board have cold or broken connections? And need re solder?? <- this I scared the most.
I did already order new boards for main board and TCON, But when i wait for board to arrive, Stil I am fighting with that problem.
Ps, I dont have old phone to be able do service remote...
Please HELP
I think I figure out problem of ghosting on the oled screen. I am in shock. You will be also when You find out that. I will attach screen shot of that problem. Probably is overheated picture processor on the main board. 
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