Yep, those are the ones.. Inspect the ends and make sure they are clean and no broken traces.. Then re-insert them into their connectors..
You can also further track down the problem by leaving one disconnected and powering up the TV... do that for each one..
Also, inspect the tab bonds that are molded into the display panel.. Make sure there are no breaks or tears.. Next to a cracked screen, tab bond damage is the biggest danger when removing and replacing the panel. What I usually do is gently bend the tab bond board to the front of the panel and apply a piece of masking tape to hold the tab bonds and board out of harms way..
I kick myself now that I didn't mention it earlier.. I sure hope that's not the problem or I'll feel like doggy doo doo.....
Thanks for all your advice. I will look at the tabs etc today. Regarding tracking down the problem by disconnecting one tab at a time, is this because one "failing" tab would stop the panel working?
Thanks for all your advice. I will look at the tabs etc today. Regarding tracking down the problem by disconnecting one tab at a time, is this because one "failing" tab would stop the panel working?
It's possible.. It could indicate a fault in one of the tabs (probably noticeable) or a fault in the TCON (not so much..)
It's unlikely that such a fault is a result of the LED replacement.. I am hoping it's just a mis-alignment of the connector tabs themselves..
Interesting! I did what you suggested, and found that if I unplugged one of the tabs then the TV would partially work, and not reboot constantly like before. The right side of the panel showed a picture which looked pretty good although there were a few horizontal lines through it. The left side was light grey but no picture.
What is strange is that I thought I'd got the problem isolated to that tab. But when I tried moving the tabs onto different connectors the results were inconsistent. For example, swapping the "working" tabs between right and left did not light up the left of the panel.
I can't see any damage on the connectors or tabs, or any strains or bends on the tabs that connect directly to the panel via the left and right boards. I cleaned everything carefully too.
So, I guess I will try a new tcon board and set of tabs. What worries me is those horizontal lines, though - perhaps I damaged the sellophane tabs on the left and right sides of the panel when I was putting the bezel on?
It's likely not any of the connectors that are bad.. It's likely either a TCON or the tab bonds molded to the panel..
Not to be a downer, but it's unlikely anything you did damaged the TCON..
Inspect the tab bonds molded to the panel closely.. Use a magnifying headset if you have one.. I had an issue with a 4K LG that inspection of the tab bonds produced a small burn in the tab bonds..
The horizontal lines, in and of themselves shouldn't be an issue.. One the TV works fine totally, it's likely you can fix the lines issue by pulling off the side tabs on the side where the lines show up.....
But I wouldn't worry about that until you can get a full picture on the display panel..
I've examined the tabs carefully, looking on both sides, with my magnified headset. I can't seen anything that looks suspicious. There aren't any areas that even look strained or sharply bent. I'm puzzled.
There are four long thin boards that hang from the tabs. The inner two are connected to tcon and the outer two are connected via a small cable to the inners. I found that with everything connected the TV reboots, but if I disconnect a single cable (any of the tcon cables or even one of the board-to board cables then the TV stays on. Depending on the configuration of what's plugged in the display shows different things. The best I've got so far is a 3/4 picture, which is better than nothing.
I know you don't think it's likely to be the tcon, but I'm not sure what I should check out next.
If you are getting horizontal lines, it is unlikely that you will get a "full picture" without disconnecting the small cables in the bottom corner of the panel on either side. The cables interconnect the bottom edge boards to the side edge boards. If you keep all the cables connected from the tcon to the panel and do the "disconnect one corner cable" at a time, you will likely find one side will produce a complete display while the other will likely get nothing or the tv won't even start up. You can go from there.
PS. I just saw your most recent post. Do the test as I suggest. Anyways, your problem IS NOT a tcon problem. It is a panel problem related to an issue with the tabs on the side of the panel. Post a picture of the display following the test I suggest.
There are no cables in the bottom corners and no side edge boards, only 8 little tabs on each side that stick out about 1/3".
There are 4 boards along the bottom. Depending on which ones are connected to each other I get different effects, shown in the attachments. First one is boards 1 and 2 disconnected, second is boards 3 and 4 disconnected, third is both 1 and 2 and 3 and 4 disconnected.
not sure if we are talking the same "language"... :-) you indicate earlier that you are seeing horizontal lines but in your picture I see only vertical lines.... some one is looking "cross eyed"... :-) but maybe the first one shows some horizontal lines... hard tell with the angle and not knowing what the actual display is supposed to be.
Anyways, IF your set has no edge boards along the sides, then the last tab on the bottom corner is responsible for providing signal (and stuff) to both the vertical portion of the screen (for that section) along with signals that go "thru" the panel up to the tabs along the side.
Your 2nd picture is kind of telling that there is a problem on the other side... as by disconnecting the 3/4 board, no signal is getting up to that side and the tv is relying on the signal going up the other side... BUT as you see nothing is happening.... because the other side has a problem.
The 3rd picture is somewhat telling that there might also be problems on the bottom on the side with the vertical colors.... is that the same vertical area that is showing no display in the first picture? Those might be an issue as the bottom tabs must remain in place. You might want to check the edge boards to see if any SMD components have failed (caps or resistors).... but I fear that this set is not salvageable because you have problems in both the bottom and sides.... but maybe I am not seeing things correctly.
Sorry I was confusing. These pictures are not really examples of the horizontal lines. I referred earlier to stuff I was seeing when I was only disconnecting the cables from tcon. In that case the thin boards were all connected. I got different results for each of the four cables. What I was referring to was that in a situation where pat of the panel worked and showed a decent picture there were horizontal lines. Those lines weren’t dark they actually showed a fainter version of the picture.
you may want to double check the "unclampable" cables on those boards (ie. they go towards the tcon) to ensure that they are indeed aligned properly. The vertical lines do not look good and might be caused by those cables not being connected properly. IF you are ambitious you can try swapping the two cables from the other side and see if that changes anything (note: swap as in unplug BOTH ends and move the cables and opposed to "crossing" which won't work and will cause damage).
I received a replacement TCON board yesterday and I'm going to try it tonight. Based on what you've both told me I'm not expecting this to be the issue at all but I might as well check.
My thinking is it's likely to be the tabs on the left and right sides of the panel rather than the bottom tabs to the driver boards. I was extremely careful with the panel reassembly but I did misunderstand the way the panel layers went together. I placed the panel directly on top of the diffuser and then tried to put the panel frame around the panel. The bottom edge of the panel rested on the bottom frame while the sides and top were on the diffuser. I tried quite hard to put the left and right sides of the frame on before I realized my mistake that the top, left and right frame sides needed to go on first and have the panel rest on it. Given the amount of pressure I applied to try to get the frame to fit I probably pushed down on the tabs on the left and right sides.
The tabs don't look physically damaged but I should inspect them more closely. However, when the TV is powered and I wiggle some of the tabs the display does change (and, at one point caused the TV to "power cycle").
So, the bad news is that I might be screwed but I do think it's likely the bottom tabs are ok.
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