Sharp LC-70LE650U - Progression of Problems

[Nanak]

Hello.

I have a Sharp LC-70LE650U that has had multiple problems while I've continued to get it working.

History of TV
1. TV sudden stopped working and displayed blink code; 1 short followed by 3 long. Owner of the TV took it off the wall and left it sitting indoors for almost a year now.
2. I replaced the PSU with one from electroparts and it wouldn't provide any power to the TV. The green light on the main board didn't light up and the TV showed no signs of power.
3. Ordered a second PSU with the exact revision, type, etc. This cleared the error code, the back lights turned on and there was a solid picture - problem solved.
4. About a week or two later there was a dark spot dead center that spread left and right as well as a green tint. Plus the right side(facing TV) was ghosting/slow to respond. The image would remain after turning the TV off. Pulled T-CON cable on left(facing front of TV) and left side displayed pure white while the right side displayed a perfect picture. Did the opposite by pulling the right T-CON cable(facing front of TV) and the right side displayed pure white while the left side displayed a perfect picture.
5. Ordered T-con; exact revision and model, an LVDS cable and installed. Told owner not to mount TV back on the wall and use it as normal. Things were fine and then he mounted it back on the wall without my knowledge, which eventually resulted in similar issues as number 4.
6. Cleaned T-con cables, hooked them back up and then the TV began to display the same blink code as before - 1 short and 3 long. It would only turn on when one T-CON cable was disconnected. Except now the white side would sometimes have horizontal patterns, but no black lines.
7. At this point I took that TV home and began to dig into it since the owner wrote it off as a loss and I was tired of using the floor as my workspace.

I've read previous posts on this forum about pulling the tabs as a last resort, but I have a few questions before I do that. I've attached some pictures of where I'm at with the TV. Left and right are from looking at the front of the TV.

sec_left_disc_facing_netflix - This is with the second T-con, both cables connected and the left corner ribbon cable disconnected. Vertical lines and dark spot in center of screen.

sec_right_disc_facing_netflix - This is with the second T-con, both cables connected and the right corner ribbon cable disconnected. More vertical lines and white spot in center of screen.

org_left_disc_facing_netflix - This is with the original T-con, both cables connected and the left corner ribbon cable disconnected.

org_right_disc_facing_netflix - This is with the original T-con, both cables connected and the right corner ribbon cable disconnected.

I'm not sure what direction to go. I've inspected all tab drivers, left and right. None appear to be burnt. I've tapped them by hand and with a spudger - no change. I've tapped the T-con cables - no change. It doesn't appear to be temperature related because I can fire the TV up the next day and the results are the same. I've tapped around the bottom of the TV and there's still no change. The only way I can induce a change is to switch the T-con.

I have a third and final T-con that says it was tested and working by the seller. Before I slap that into the TV, are there any other tests or readings I can check with my DMM?

[mmartell]

Re: Sharp LC-70LE650U - Progression of Problems

Your second tcon has an issue.

Your horizontal driver issue appears alleviated in the last pic so it's on the side of the disconnected corner cable - so right side uppermost driver.

It's also possible you have a failed vertical driver or tab bond issue. Try touching that tab lightly to see if the lines change at all.

You may have to remove the drivers on the right side and see how the vertical lines are affected.

[budwich]

Re: Sharp LC-70LE650U - Progression of Problems

its doesn't look good. You should probably check the lower right corner edge board to see if there is any physical damage. It could be that, as mmartell suggests, that one of the side tabs is "pulling down" the vertical source driver on that side. There have been instances of the "tab removal" clearing up both horizontal and vertical issues... I guess it depends on the position and tracks within the panel as to how things are routed / designed.

It is rather strange that "wall mounting" causes a problem but perhaps the "action of mounting" (twisting, positioning, handling in general) is the root cause resulting in panel problems which impact the tabs / drivers.

[Nanak]

Re: Sharp LC-70LE650U - Progression of Problems

Thanks, mmartell and budwich.

I agree with you about the handling of the TV during the mounting being a factor. Last night I decided to put the second tcon back in the TV and have a new set of results. It really seems like everytime this TV is touched, something new happens and I haven't touched the TV since my first post.

I'll have to do it again to make sure I'm not posting incorrect outcomes, but at this point the backlights won't turn on with the original OR second tcon if the left tcon cable(facing the tv) is connected. I also tried both tcon cables on the left side and it's the same, so that rules out a bad ribbon cable. Completely different results since last time. When I did get it to turn on(connected only right side tcon cable) I again tapped all 5 side drivers on both sides and tapped on the top of the TV. It just doesn't change the picture at all. It's probably not the best, but I have a blanket on a table and the face of the TV rests on that when I'm swapping tcons and working with the ribbon cables. I lift the TV up from the top by grasping the metal behind the panel carefully and it rests against the wall when I check the picture.

If I have to check vertical drivers, do I need to remove the metal at the top and bottom of the TV?

I have not put my 3rd tcon in the TV. Do guys think I should not put it in until further investigation of the tabs?

I'll post pictures of the tabs and have the exact outcomes soon.

[Andrew F. Ali]

Re: Sharp LC-70LE650U - Progression of Problems

Improperly hanging a large TV like that on the wall somehow cause strain on the Panel showing dark areas, lines, etc and from my experience the wall mounts should have a bottom support also.

[budwich]

Re: Sharp LC-70LE650U - Progression of Problems

you might want to put on your glasses when you are positioning the cables in the clamps... I almost get the feeling that the cables are misaligned.

anyways, check the fuses on the tcon board along with the voltages going there just in case something happened on the way to the "dance".

still further. the bottom edge boards have interconnection ribbons going between them. If you disconnect them (they are unclampable), especially on the side that has the verticals, you might see some thing different (but most likely still bad).

[Nanak]

Re: Sharp LC-70LE650U - Progression of Problems

Right. I've been using a magnifier when inserting those cables, but need to check that again. Having worked on many PlayStations that use the same kind of cables, you can usually "feel" when the cable is fully inserted before clamping it down. I'm not getting that kind of feedback from insertion with this TV.

Here's some pictures of the tabs on the right side and the left ones look similar. Do they look suspect?

The cables along the bottom that don't use a clamp, will they just pull straight out without damaging things?

I still haven't put the 3rd tcon in. I'm not sure where I would check voltages on the tcons and I don't see an obvious fuse like on the power board. If I know where to probe, I do remember freak said to only supply power, but don't connect it to the panel.

[budwich]

Re: Sharp LC-70LE650U - Progression of Problems

The "cabling" at the bottom of the set that I refer to are ribbons interconnecting the edge boards and NOT the panel. They are set in clampable connector... at least in all the ones that I have seen. Post a picture if you are unsure.

As for the tcon ribbons, there are "tangs" (cut outs) on the side that properly position the cable in the clamp in terms of "inset" (how deep the cable goes in). They are on both sides. The position of the "tang" on each side will tell if the cable is aligned based on space / lack there of.