Re: Bad T-con or bad panel??
I'll try and get a mesurement and see whats getting vcc tomorrow or Saturday....
Alternet
Member
Last Activity: 01-05-2023, 09:35 AM
Joined: 10-09-2017
Location: manitoba
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Re: Bad T-con or bad panel??
yes that side with the chipped glass is the dark side. I looked at that glass at first thinking it was the issue but it didn't appear to short that thin film line.
That's why I was asking if that dark spot is something that is common on panels.
So your thoughts are that the VCC line in the glass got shorted and thats what caused the black spot?...Leave a comment:
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Re: Bad T-con or bad panel??
Here you go. A picture of the bottom board on the tv. (this is the board for the dark side)...Leave a comment:
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Re: Bad T-con or bad panel??
I will take a picture when I can.
What is the difference between 2 boards and 4 boards? Does it split the screen into 4 sections instead of two? Or is there more to it?...Leave a comment:
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Re: Bad T-con or bad panel??
There are two ribbons that go from the tcon to the boards at the bottom. The tv has only two boards at the bottom of the screen (each board has several ribbon cables connecting it to the panel itself).
Nothing connects the two boards and the two boards are not "smaller boards" connected together. They are one solid board on each side of the bottom (though the circuitry may be as such that they have isolated parts, but I have not looked that closely at the circuitry of the boards themselves)...Leave a comment:
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Re: Bad T-con or bad panel??
The tabs in the picture are along both sides and none or connected to any external panel.
The tabs at the bottom are connected to 1 board on each side of the bottom. (2 boards on the bottom total)
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General question (for anyone that may know)
How does removing the tabs (on tv's where its been proven to work) not effect the image? Taking out one of the drivers should result in lost of a chunk of the picture, should it not?...Last edited by Alternet; 07-28-2020, 10:43 AM.Leave a comment:
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Re: Bad T-con or bad panel??
So I tried to poke at the all the tabs and no such luck with anything.
I also noticed while doing this that there is most definitely lcd timing issue.
While poking all the ribbons on the side I noticed that when the stock lg background display picture changed I could see that some pixels close to the edge of the "dark side" took much longer to change then anywhere else.
For an idea of what this looks like, think of a the sweeping effect from one side to the other. Picture first changes on the one...Leave a comment:
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Re: Bad T-con or bad panel??
Sorry everyone. I had a super busy weekend and didn't get a chance to test the tv. Will test tonight and post results tomorrowLeave a comment:
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Re: Bad T-con or bad panel??
I have another question... Say one of the tabs is bad and I had the skill to solderer and replace it. Is it possible to acquire one? or would you only be able to get one from another screen that is broken?Leave a comment:
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Re: Bad T-con or bad panel??
Yes this tv has tabs that connect to nothing on the sides and tabs that connect to the panel driver which connect to the t-con on the bottom
So your thinking its garbage?...Last edited by Alternet; 07-24-2020, 11:14 AM.Leave a comment:
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Re: Bad T-con or bad panel??
Ok i'll give it a shot tonight. I'll post results again tomorrow.
Any other tests I can run?
I'm also going to test all the resister and cap values on each panel driver board tonight and see if there is a difference between the bad and good side...Leave a comment:
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Re: Bad T-con or bad panel??
I have questions.
***This is in no way trying to challenge what you have said. I just want to learn more then what I currently know***
The drivers manage to switch from black to white with no issue (which to me says they can drive all of the R, G and B's of each pixel. I would also assume that these two states don't rely on any feedback as its full on/full off kind of thing. Would this be correct?
Also when both sides are plugged in the OSD appears unaffected by what ever the issue is (the darkness)....Last edited by Alternet; 07-24-2020, 09:42 AM.Leave a comment:
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Re: Bad T-con or bad panel??
So a few questions before the results of the test.
Does anyone happen to know if this tv or tvs in general are color additive or subtractive?
I ask because when you unplug one of the sides that side goes white. Which means the R, G and B lcds are all set to 255 (or what ever number of bits tv's use now). That makes me think its color subtractive because no signal results in all colors (which equals white)
But when either side is plugged in that side goes black at boot up when the tv is showing which input...Last edited by Alternet; 07-24-2020, 08:14 AM.Leave a comment:
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Re: Bad T-con or bad panel??
will try that tonight and take pics....Leave a comment:
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Re: Bad T-con or bad panel??
Ok well the dark side is the side that use to be the issue.
i did disconnect that side several times after it just started working again for no reason. I get a fully white screen on the "dark side" and a picture on the "good side"
I will do it again tonight and take pictures....Leave a comment:
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Re: Bad T-con or bad panel??
Ok i just want to clarify again.
so for the test you want me disconnect both ribbons from the t-con side (not at the same time) and verify that side goes white and the other has picture.
Also i don't know if this is useful info in anyway but when doing the tap method i was taping on the t-con side of the ribbon cable...Leave a comment:
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Re: Bad T-con or bad panel??
I think I might have been wrong on saying I never saw a picture. In my original post about the back lights I did say I saw the LG logo pop up for a minute. I honestly cant remember now if I did or not. But my post says I did so i have to assume the panel was able to display picture at one point and that i just couldn't see it because the backlight was dead.
Are you wanting me to disconnect the LVDS cable from the tcon or just the ribbon cables to the panel driver boards? (I cant do it right now but i will do it tonight and...Leave a comment:
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Re: Bad T-con or bad panel??
that is the lower left side (if looking from the back of the display). I don't have any other pictures right now. I can take some when i'm home tonight if that will help.
is that what you mean by tab? or do you mean the ribbons connecting the panel drivers to the panel?...Last edited by Alternet; 07-23-2020, 11:15 AM.Leave a comment:
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Re: Bad T-con or bad panel??
Just want to make sure i know what your talking about. By tabs are you referring to what I have circled in red in the attached picture.
Also i'm still not quite sure what to make of the spot pointed to by the green arrow. Is this damage from a short or is this common to see in these panels? (as I said before I do not have much experience with lcd panels)...Leave a comment:
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Re: Bad T-con or bad panel??
I'm not trying to attack you at all. Please dont take it that way. I was actually hoping you had a schematic. I was going to ask if you could send me a copy.
I was in no way trying to attack you. I'm sorry that it came across that way....Leave a comment:
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