Bad driver(s)? Sharp LED TV

[scuby]

So I recently fixed my first main board, I should say diagnosed and replaced, to get a 50" Sharp up and running again.

I've got my eye on another one that's acting up. I haven't gotten my hands on it yet. It's a gamble. But for a 5 year old tv that has seen little use at 70 inches I'm intrigued. I'm pretty sure these things divide the screen up into four sections on the LED driver side, is that right? I had 4 24v out's on the 50" and it's a similar model. Just a wild guess

It powers up fine, so for now that rules out power board issues, but only gives about a quarter of the screen and it's blue. Nothing else.

Could this be a driver issue? Happened one day to the next. No falls or anything like that, just boom: it's like this, see attachment.

It's not a lot to go on but any ideas? input? what to look for?

I can pull the back off and get relatively far with my DMM but untill then I'm looking to get as much info as possible on probable problems. A lot of p's there...

[scuby]

Re: Bad driver(s)? Sharp LED TV

at this point I have this TV

The backlight lights up. It has sound. it shows no image whatsoever.

The first few minutes it gave the blue screen as shown in the pictures above. Though it did stay on the left side size and shape changed a little per power cycle. Once it filled the screen with a purplish hue, the entire screen, giving me some confidence that the LCD panel itself is ok.

After a few cycles the screen remains blank. The backlight working and sound as well.

Am I to suspect a faulty T-con board? or could it be the main board graphics processor?

I suppose both. Neither have any visible issues with capacitors etc.

A recent fix of a 50" Sharp LCD LED was the replacement of the main board. I was told a common error: that TV refused to boot up though.

This one starts up. Just no picture.

The European model designation is: LC-70LE835E
The US model designation is: LC-70E735U

[scuby]

Re: Bad driver(s)? Sharp LED TV

I just disconnected the Tcon ribbons carefully and I was able to get a full white clear screen on each half. The first time the left half was fully white and right half looked like it had been smashed! all kinds of lines and colours. Put it all back, fired the tv up: blank screen again.

Pulled the ribbons again. This time the right half was fully white and the left half mostly grey.

Is it safe to conclude the panel itself is ok?

Bueller?

[scuby]

Re: Bad driver(s)? Sharp LED TV

Here are some pics.

[nomoresonys]

Re: Bad driver(s)? Sharp LED TV

Can try cleaning your tcon ribbon cable ends, some use a pencil eraser, also make sure you have a good and clean connection at the lvds cable going from mainboard to tcon, could be a faulty tcon.

[scuby]

Re: Bad driver(s)? Sharp LED TV

Can try cleaning your tcon ribbon cable ends, some use a pencil eraser, also make sure you have a good and clean connection at the lvds cable going from mainboard to tcon, could be a faulty tcon.

thanks. Can I rule out either mainboard or faulty panel? Is Tcon the most likely?

[Diah]

Re: Bad driver(s)? Sharp LED TV

I just disconnected the Tcon ribbons carefully and I was able to get a full white clear screen on each half. The first time the left half was fully white and right half looked like it had been smashed! all kinds of lines and colours. Put it all back, fired the tv up: blank screen again.

Pulled the ribbons again. This time the right half was fully white and the left half mostly grey.

Is it safe to conclude the panel itself is ok?

Bueller?

did you got the white screen when you disconnected the ribbon with signal or with out ? you need with signal to see if half screen come out with picture... if you did it with signal then you have much likely issue on main boards

[scuby]

Re: Bad driver(s)? Sharp LED TV

did you got the white screen when you disconnected the ribbon with signal or with out ? you need with signal to see if half screen come out with picture... if you did it with signal then you have much likely issue on main boards

I disconnected them wihtout signal and with the power off.

I should do this test with the set on and a signal playing?

What am I looking for?

[nomoresonys]

Re: Bad driver(s)? Sharp LED TV

Well I don't think you can rule out mainboard, tcon or panel yet, it can be tricky pinpointing a problem, probably why a lot of people start with throwing a replacement tcon at it if they can get one cheap enough, nice testing video here, he checks the power and mainboards over and Budm posted a tcon checking procedure the other day: https://www.youtube.com/watch?v=ocqnqmBxiqY

[nomoresonys]

Re: Bad driver(s)? Sharp LED TV

The tcon training is post #29 there: https://www.badcaps.net/forum/showthread.php?t=76056

[scuby]

Re: Bad driver(s)? Sharp LED TV

cheers

some of might be a littel too finnicky for me. I'm a mechanic by trade and the fiddly stuff gets me under my skin

I'll have a good look day after next. Meanwhile I've orderd a Tcon for 22 euro's because, well honestly I'm hoping to throw a part at it and have that work.

I also need to pick up finer pointed probes for my dmm.

Is it worth mentioning that the television is not flashing any error codes? I'm not sure what kind of diagnostic this TV is capable of but perhaps worth noting...

Either way I'll give this all a read over again tomorrow. The Tcon trainng is on a Samsung. am I looking for similar if not identical voltages in and out on my Sharp? Where can I get that information if there are variations?

[nomoresonys]

Re: Bad driver(s)? Sharp LED TV

Very good question, I don't know if they are all the same, I usually just throw a tcon at it, if cleaning cables don't work, unless it's something very obvious like a bad fuse or such. Not much patience for dealing with the real small components that might be involved.

[RJARRRPCGP]

Re: Bad driver(s)? Sharp LED TV

Being a Sharp, check this thread:

https://www.badcaps.net/forum/showthread.php?t=48477

Series LC-XXLEs are the worst offenders!
(The XX, is the place holder for the 2 digits of the screen size, in inches.)

[scuby]

Re: Bad driver(s)? Sharp LED TV

Being a Sharp, check this thread:

https://www.badcaps.net/forum/showthread.php?t=48477

Series LC-XXLEs are the worst offenders!
(The XX, is the place holder for the 2 digits of the screen size, in inches.)

cheers.

The LE's are the wost offenders in what way? I'm reading a bunch of symptoms/solutions. Worst offenders in panel failure?

Seems so strange to me that the panels fail one moment to the next. I have no codes. I'm still not clear on the Tcon ribbon unplug test that proves a faulty panel (and why/how). Any insight?

Thanks for the help folks. Much apreceated.

[scuby]

Re: Bad driver(s)? Sharp LED TV

Very good question, I don't know if they are all the same, I usually just throw a tcon at it, if cleaning cables don't work, unless it's something very obvious like a bad fuse or such. Not much patience for dealing with the real small components that might be involved.

basically my train of thought too

[budwich]

Re: Bad driver(s)? Sharp LED TV

you should still try doing the "cable removal test" again and feed in an input signal. Depending on the outcome, it will readily point you in a direction.

[scuby]

Re: Bad driver(s)? Sharp LED TV

you should still try doing the "cable removal test" again and feed in an input signal. Depending on the outcome, it will readily point you in a direction.

Ok. I need a clear guide on that test. Could be me but I'm not reading a consistent methodology.

Give it a signal: verified by audio

Remove outer Tcon cable (I have four). That half should go white?

Reconnect and remove opposite and that half should go white?

Don't need to remove the inner cables?

My backlight always comes on. I have no codes flashing.

thanks

[scuby]

Re: Bad driver(s)? Sharp LED TV

allright: here's wat I've done:

I have 4 cable/ribbons running from the Tcon to the panel. My backlights always come on every time I power up the set. I have no codes flashing at any time.

I have a source playing verified by it's audio.

Unplug the right most cable/ribbon: corresponding half of screen lights up mostly white/grey but lot's of colored lines. See Pic 1

Unplug the second cable from right: corresponding half of screen goes completely white. See Pic 3

Same is true of the left. 1 cable results in a more colorful lighting up of the screen. Disconnect both it's all white. See pic 2, it goes fully white like pic 3 on the other side too.

Disconnect all four and the set switches off.

What can we conclude from this?

[RJARRRPCGP]

Re: Bad driver(s)? Sharp LED TV

cheers.

The LE's are the wost offenders in what way? Worst offenders in panel failure?

Yes, they're the worst offenders of panel driver failures, if not also deep into the panel!

[scuby]

Re: Bad driver(s)? Sharp LED TV

I followed this procedure to reset the set (even though I have no codes).

Unplug set. Hold down Vol - & Input while plugging set back in, release. TV powers up and shows variations of the following image (see attachments). A partial blue screen. Which can hold, flash off for a second and back on. I can't get any menu or other image to show.

After the reset I cannot see a "K" as suggested by some posts.

Hope this helps narrow things down. I can get a Tcon locally quickly relatively cheaply. Is it worth it? Or has this panel suddenly and dramatically died? Astounding how many Sharp Tv's have issues out there!

Please ignore the mess. I'm in the middle of a divorce and living in my office. The TV working would be a good thing come the holiday's lol

thanks again.

PS: with one side disconnected from the Tcon the white side will dimm after a few seconds as if saving power. Hitting the menu button or volume will trigger the screen to illuminate fully again. It seems to respond that much at least. It also does this when displaying the blue screen which varies in size when turned off and on again but is always on the same side.

Hoping for input. Cheers