Sharp LC-70LE55OU No video

[bradam]

So my 70 inch sharp TV decided it doesn't feel like displaying any picture anymore

If left off for a while, when you very first turn it on, you get picture for a few seconds then it freezes and kind of fades away, but the backlight stays on. You can turn the tv on and off again but you just get a backlit screen. The white led in the bottom front stays lit up white and doesn't flash at all that I can notice for codes.

Tried factory reset, leaving it sit unplugged a few days, same issue.
Bought a new power supply hoping that was the culprit but same issue. So I tried replacing the Tconn board but still no picture.

Oddly enough if you disconnect one of the 2 ribbon cables connected to the Tconn board you can get picture on one side of the tv screen or the other. However one of the sides will stay on but with the other ribbon disconnected that sides picture fades out after a few seconds.

So I'm guessing its not the main board but a problem with the panel itself possibly?

Any help/suggestions is much appreciated!

[leggot]

Re: Sharp LC-70LE55OU No video

I would guess that you have a loose connection with one or more of the ribbon cables, try wiggling them around/reseating them. I have had situations where you can shim ribbon cables at their point of connection to get a good signal.

Another good test is tapping the connections to see if that fixes the issue, that would be a good indicator of a loose connection.

[bradam]

Re: Sharp LC-70LE55OU No video

With them both plugged in you initially get picture but it quickly fades away, its only with one of them removed there is a difference.

If your facing the back of the TV and disconnect the right ribbon cable then walk around to the front of the TV the left side of the screen is white, but the right side has picture and it stays on.

If your facing the back of the TV and disconnect the left ribbon cable then walk around to the front of the TV the right side of the screen is white, but the left side has picture for a few seconds then it fades out and goes black.

So that made me wonder if there's something possibly wrong with left side of the panel?

Also found it odd that with one of the ribbons disconnected the tv powers on and doesn't flash any error codes.

[leggot]

Re: Sharp LC-70LE55OU No video

Have you tried any of the tests I mentioned in my last post? Hopefully they will help determine if this is infact a connection issue with the ribbon cable. It is relatively safe to touch the ribbon cables when the tv is in operation as long as you stay away from the power and inverter boards where the high voltages are.

If this doesn't work it may be a heat sensitive issue or a tap bonding issue; however its best to eliminate one issue at a time.

[mmartell]

Re: Sharp LC-70LE55OU No video

Sounds like a panel issue.

[bradam]

Re: Sharp LC-70LE55OU No video

Have you tried any of the tests I mentioned in my last post? Hopefully they will help determine if this is infact a connection issue with the ribbon cable. It is relatively safe to touch the ribbon cables when the tv is in operation as long as you stay away from the power and inverter boards where the high voltages are.

If this doesn't work it may be a heat sensitive issue or a tap bonding issue; however its best to eliminate one issue at a time.

Ended up setting up a mirror on the other side of the tv so I could see heh

Short of straight disconnecting the ribbons I saw no difference tapping or wiggling them

[bradam]

Re: Sharp LC-70LE55OU No video

Is there any repairs that can be done on the panel? Ole google is failing me on that one.

[leggot]

Re: Sharp LC-70LE55OU No video

Try using a hairdrier to heat up the connections or compressed air can upsidedown to cool down the connections to see if that makes a difference.

Otherwise, if you eliminated the tcon board, then it could be a bad ribbon cable or panel, I doubt that its bad bonding.

[bradam]

Re: Sharp LC-70LE55OU No video

The replacement ebay tcon board came with 2 ribbons attached, tried both boards with both sets of ribbons, same problem either setup.

[nomoresonys]

Re: Sharp LC-70LE55OU No video

see if you can find a firmware update, couldnt hurt.

[leggot]

Re: Sharp LC-70LE55OU No video

Have you tried messing with the other end of the ribbon cables attached to the main board?

[nomoresonys]

Re: Sharp LC-70LE55OU No video

could try cleaning your tcon cable aka lvds cable contacts with an eraser, I think you can clean the tabs to the tcon too.

[bradam]

Re: Sharp LC-70LE55OU No video

Have swapped out the ribbon cables, they appear fine though. No signs of corrosion or anything. It takes a bit of finesse to get them on and off the bottom of the tv.

Was fiddling around trying to update the firmware but I can only see half the tv screen and can't read the steps.

[freakaftr8]

Re: Sharp LC-70LE55OU No video

It does sound like a panel issue to me too sadly. shorted voltage on one side of the panel. with both plugged in in the initially get a picture and it fades away and if you unplug one side and it stays on that definitely sounds like a panel problem. you could always go for the t-con board but I really don't think it's going to fix matters unfortunately