Sharp LC-70uq17u 3-4" vertical black bar

[jrobie79]

Client from work was getting rid of this TV because she said it had a 3-4" black bar on the right side of the screen, top to bottom.

I replaced a few boards in my old Panasonic plasma, so I took the back off to look around and noticed one of the grounding screws in the video board was missing, I optimistically thought this was the issue, slapped a new one in and tried it out. Black bar is still there. Any recommendations? Is this beyond repair (panel issue)? Or is there something specific I should be looking for/board to replace?

Picture below:

[budwich]

Re: Sharp LC-70uq17u 3-4" vertical black bar

check and clean all cable connection going to and from tcon and at the edge boards on the bottom of the set. What happens if you disconnect the tcon cable for this side. The screen should go white for that half.

[jrobie79]

Re: Sharp LC-70uq17u 3-4" vertical black bar

check and clean all cable connection going to and from tcon and at the edge boards on the bottom of the set. What happens if you disconnect the tcon cable for this side. The screen should go white for that half.

I'm gonna take the TV down and check tonight. Any product you recommend for cleaning or just some air in a can?

[dick_barton]

Re: Sharp LC-70uq17u 3-4" vertical black bar

Is the mark a reflection off the screen?

[jrobie79]

Re: Sharp LC-70uq17u 3-4" vertical black bar

Is the mark a reflection off the screen?

yes thats the flash from my cell phone camera, or its a magentic drop light attached on a car on the lift behind me taking the picture. I probably could have found a better picture to show the black area

[budwich]

Re: Sharp LC-70uq17u 3-4" vertical black bar

did she also tell you that she "washes" the screen... :-)
You might check the bottom edge boards to see if there is any sign of "contamination". I do believe on these set, if you disconnect the tcon to panel cable, the associated section goes white.

[jrobie79]

Re: Sharp LC-70uq17u 3-4" vertical black bar

did she also tell you that she "washes" the screen... :-)
You might check the bottom edge boards to see if there is any sign of "contamination". I do believe on these set, if you disconnect the tcon to panel cable, the associated section goes white.

I'll advise tonight on what I discover.

[jrobie79]

Re: Sharp LC-70uq17u 3-4" vertical black bar

So this is what happened when I unplugged the left side (looking at the board) tcon ribbons.

Looks like the issue is the panel huh? Oh well, it was worth a shot.

[budwich]

Re: Sharp LC-70uq17u 3-4" vertical black bar

giving up... depends on whether you want to "fix" OR "save" the set ... :-).
It is unlikely that you will be able to fix it because of the issue BUT it might be "saveable"... ie. "normally" operatable with no black bar.

Of course, I understand time is money so perhaps it is a waste at this point.

The test you have done only shows the result from "stimulas" sent from the TCON. However, it might be possible that "stuff" is finding its way around from the side... possibly thru a shorted capacitor.... maybe

Repeat your testing with the same tcon cable disconnected AND also disconnect the small corner cable that interconnects the bottom edge boards to the side boards (look for clamps in the bottom corner at each side). This might possibly break another "potential path" that is finding its way to the lower boards on that side. Just a "postulation" on my part based on result that I have seen and now you have confirmed again. Of course, while you are looking at the bottom edge boards, maybe look at some of the components in that corner to if anything stands out.

[jrobie79]

Re: Sharp LC-70uq17u 3-4" vertical black bar

Of course, I understand time is money so perhaps it is a waste at this point.

The test you have done only shows the result from "stimulas" sent from the TCON. However, it might be possible that "stuff" is finding its way around from the side... possibly thru a shorted capacitor.... maybe

Repeat your testing with the same tcon cable disconnected AND also disconnect the small corner cable that interconnects the bottom edge boards to the side boards (look for clamps in the bottom corner at each side). This might possibly break another "potential path" that is finding its way to the lower boards on that side. Just a "postulation" on my part based on result that I have seen and now you have confirmed again. Of course, while you are looking at the bottom edge boards, maybe look at some of the components in that corner to if anything stands out.

I have plenty of time, it's just a garage TV, so I can probably tolerate the black bar even if I can't get rid of it. Mostly there's a ball game on, or I pull up youtube videos if I'm working on the car to see how some stuff is done. It's still vastly superior to the old 40" I had in there, too damn small. I'll take a look when I get home from work.

It's just so hard to have a good view of all the bottom boards because its so damn heavy. I checked the right side edge boards connecting ribbon cables but the boards themselves appear to have a permanently mounted ribbon cable? I'll report back. Thanks a ton!

[jrobie79]

Re: Sharp LC-70uq17u 3-4" vertical black bar

Repeat your testing with the same tcon cable disconnected AND also disconnect the small corner cable that interconnects the bottom edge boards to the side boards (look for clamps in the bottom corner at each side). This might possibly break another "potential path" that is finding its way to the lower boards on that side. Just a "postulation" on my part based on result that I have seen and now you have confirmed again. Of course, while you are looking at the bottom edge boards, maybe look at some of the components in that corner to if anything stands out.

So I disconnected the ribbon cable from the bottom board to side board. That side is no longer white (T-Con board still disconnected on that side) however there is a uniform "glow" that appears to extend all the way to the edge, no clear black bar. What board should I be looking for damage/issues on? The side? If the bottom, can I flip the tv upside down for a bit to get at all the screws to look at the bottom board or will that damage the panel?

[budwich]

Re: Sharp LC-70uq17u 3-4" vertical black bar

I hope I understand your test right... so basically, you have taken away any "path" from the tcon to the side that had the totally black bar... which now has "disappeared"... right?

I was hoping that the "totally disconnected side" would now be all "white". :-(

Are you feeding a signal into the tv at this point?

be careful about moving this big tv without the framing in place. The panel will / may flex and crack.

Anyways, put back the tcon cable (power off of course). leave the corner cable disconnected.... what happens to the display?

[jrobie79]

Re: Sharp LC-70uq17u 3-4" vertical black bar

Everything framing wise is still in place. The only thing removed is the back cover. When I discovered the other side of the t-con ribbons the side that had no picture issues was white, but the connected side (black bar) did not display haha the sharp logo and was flickering a whitish color. I'll try to get a couple pics of that as well.

[budwich]

Re: Sharp LC-70uq17u 3-4" vertical black bar

no sure I understand what you are "typing"... :-)
please re-read and restate what is disconnected and where (eg. at the tcon, at the side edge board, at the bottom edge board etc).... cause I don't understand your "When I discovered the other side of the t-con ribbons...".... do you mean "disconnect" instead of "discover"... ?????

[jrobie79]

Re: Sharp LC-70uq17u 3-4" vertical black bar

no sure I understand what you are "typing"... :-)
please re-read and restate what is disconnected and where (eg. at the tcon, at the side edge board, at the bottom edge board etc).... cause I don't understand your "When I discovered the other side of the t-con ribbons...".... do you mean "disconnect" instead of "discover"... ?????

Found the culprit... Bottom board ribbon cable is fubar... Is this replacable? The ribbon is integrated with the board (on this end), any chance I can replace that whole board and the other end is removable?

[budwich]

Re: Sharp LC-70uq17u 3-4" vertical black bar

:-(
I guess she did wash the screen... :-( :-)

Too bad, it is non-serviceable. Don't take my "wash comment" to seriously, as there was also a potential that the board holder / clamp was "bad" and as a result the board / cable might have touch the frame... although I am not sure it would have caused the damage that you show.


but wait... the other end is "clampable".... what is it connected to?

[jrobie79]

Re: Sharp LC-70uq17u 3-4" vertical black bar

but wait... the other end is "clampable".... what is it connected to?

The exterior looks scuffed in that location, so it was probably dropped. I'm not sure if the other end is "clampable", I haven't taken it apart that far yet. It appears to be routed to the front, so possibly the panel itself? Are those typically "clampable"? If so I think I could replace that whole board? Is it impossible to repair ribbons? My father is an electrical engineer, with access to plenty of fine intricate tools, just not sure if it's even possible.

I'm gonna live with the bar regardless, but it'd be nice to be 100%

[budwich]

Re: Sharp LC-70uq17u 3-4" vertical black bar

I have seen pictures of a "fix" where by the person "jumpered" around the solder connection points at the edge board (must have been an issue there) but never seen anyone attempt to fix a tab cable itself. There isn't much to attached to in the cable. In your case, I would leave it alone.

If it is unclampable, that would be worth a try.