Re: LG display sporadic screen issues
update:
I searched for the FRC board for several months; hoping one would come available, with no success. I finally decided to order one that had the same IC part number, knowing this was a stab in the dark. After receiving the board and placing it in the unit I found myself back at square one as the replacement board didn't work. I went ninja on the old FRC board to see if I could visually find what was wrong with the board. I had looked at it several times before to no avail. I hadn't found any broken or burnt traces, no fat capacitors,...
thedosmann
Member
Last Activity: 12-29-2013, 10:01 AM
Joined: 05-26-2013
Location: munford, tn
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Re: LG display sporadic screen issues
kLeave a comment:
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Re: LG display sporadic screen issues
What areas should I concentrate on, power, inverter, frc, t-con, mainboard? Also the frc is tight underneath and hard to get to so it would be hard to get to it with a shot cold air, I will try.Leave a comment:
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Re: LG display sporadic screen issues
Using a hair dryer at various locations in back did not have any effect. The unit stayed up and running until today, so pretty much 2 days, when the screen messed up. Would it be a total waste of money to try another t-con board?Leave a comment:
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Re: LG display sporadic screen issues
No, but I guess I can get the hair dryer out and start aiming it at different locations and see what happens. I'll let you know.Leave a comment:
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Re: LG display sporadic screen issues
Well it started messing up again. It will go into a period of sporadic screen distortions and then straighten out and stay that way until it starts messing up again. It could stay ok for a while before it starts messing up again. Sometimes it will be distorted on a power up sometimes not but it will eventually show a good screen.. until it starts messing up again. I've done tap tests at several locations with no effect. T-con board?Leave a comment:
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Re: LG display sporadic screen issues
Finally got back to this. I put the old t-con back in to check if that is what went out. I expected to see the same behavior that made me replace it. Instead it looks like the original issue, but can't be sure. Right now it's working with no issues. Couple of questions:
Does the orientation of the panel ( IE: upside down, flat, laying face down, ...) affect normal operation of the panel?
Are Gremlins real?
At this point I can only wait to see if it messes up. If it does I'm thinking I got a bad t-con from ebay and...Leave a comment:
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Re: LG display sporadic screen issues
K..will do. The pic your looking at is right after I loosened board and turned over to view. I'm not at the unit right now but enlarging pic doesn't show them touching. I think this was build indicator on where to plug in?Leave a comment:
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Re: LG display sporadic screen issues
I double checked that. I took a pic before I detached everything and it showed the original alignment. Do you see something off?Leave a comment:
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Re: LG display sporadic screen issues
There is a board in between the mainboard and t-con, I think it is an FRC board I managed a tight pic of it below. It looks like the t-con went out again since it is getting 12+/- at both ends of F1(curious as to why t-con went out again. I'm thinking I should get another t-con and also the FRC board? Presently there is no picture but back light is on and T-con is getting the juice so am I correct to follow this path? That is if I can find another T-con and also the FRC board.
The t-con part# is68700-0402c the chip is lg5822
The...Leave a comment:
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Re: LG display sporadic screen issues
No obvious problems anywhere. Checked v on F1 of t-con and it shows 11.87 on both ends with back light on. Is there a fuse beyond that or where to from here?Last edited by thedosmann; 06-05-2013, 04:34 PM.Leave a comment:
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Re: LG display sporadic screen issues
It doesn't matter now because it lost picture again. Back light still glowing but no picture..just black screen. I will look at the boards to see if something blew.Leave a comment:
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Re: LG display sporadic screen issues
Is it possible the tab-bound fix may have may have created too much of a bond causing it to take time to properly connect? Once the set is on for a few hours I can disconnect the input and while it goes into power down countdown I can reconnect the input and no issues show. If I let it power down and wait a minute or two and power back on it starts with the bad behavior again for a few minutes. Also, the sides of the panel metal frame get very hot to the touch not the top and bottom just the sides. I can hold my fingers on it but it's very ...Leave a comment:
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Re: LG display sporadic screen issues
Thanks for the reply. I will take another look at the boards. Do you suggest an area to concentrate on? Power, inverter, ..I have replaced the t-con and main board so I feel they should be OK?Leave a comment:
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Re: LG display sporadic screen issues
I've replaced the main board, t-con board, and applied the tab bond fix as described here - [URL="http://www.youtube.com/watch?v=purk_SyiT44"]http://www.youtube.com/watch?v=purk_SyiT44[/URL].
Currently when I power on it will blink to black screen, distort, or otherwise mess up for a second or two and go back to a normal screen. This happens about every 5-10 seconds. This becomes less frequent the longer it stays on until it seems to stop messing up completely. I'm not sure if it completely quits doing this as I cannot watch...Leave a comment:
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Re: LG display sporadic screen issues
It seems somewhere in the mix the t-con did go out. I replaced it and the screen is displaying ok but intermittently messing up. It will either blink off for a second or distort for a second and go back. It is happening every minute or so or sometimes it will wait for a few minutes. I checked the shims and still little or no distortion if I push in on the ribbons.
Edit
The longer it stays up the less frequently it messes up.Last edited by thedosmann; 06-04-2013, 07:22 PM.Leave a comment:
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Re: LG display sporadic screen issues
With the PC board as input it doesn't power down and the screen remains white.Leave a comment:
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Re: LG display sporadic screen issues
Below are some pics of the boards. When I power on it shows a white screen that goes to black in a few seconds. Either the component that was going out went or its another issue. It only stays lit for a few seconds but I can see the power down countdown just faintly before it goes black sometimes....Leave a comment:
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Re: LG display sporadic screen issues
The Tab - bond fix doesn't seem to apply. I followed the directions and touching the ribbons has no effect. I went ahead and added the shims but no effect. The problem has changed now to going to a black screen shortly after power on. Sometimes it will show a good screen for a second and sometimes a white screen with the power down countdown barely showing. After a few seconds it just goes to a black screen.Leave a comment:
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Re: LG display sporadic screen issues
Well, it went south this morning. So I'm off to Tab-Bond land. The touch glass will complicate this a tad but let's see what I can tear up.Last edited by thedosmann; 06-03-2013, 02:00 PM.Leave a comment:
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