Can you tell me what is wrong with this LCD from the pictures? - Videokarma.org TV - Video

similost · #1 09-21-2009, 08:22 AM

I had to come into work over the weekend to power down and then back up all the servers, PC, and televisions here in the office for a power outage.

This is a 46 Sharp Aquos. I turned it off before the power went down, then when I turned it back on, this is what I had. I've got 5 of these in the office, and the other 4 were fine. They stay on all the time, just no source fed to them when not in use. They are only turned off maybe once a year.

The first picture is with the cable as a source using RBG BnC connectors. it changes a little as the scenes change, but not much. The second picture is with a PC as the source over VGA.

Any ideas? Is this unit shot, or do you think it would be repairable.

leadlike · #2 09-21-2009, 08:44 AM

Well, before tearing it down, make sure no one was fiddling with the settings, ie, refresh rate, etc.

Most LCD screens consist of only 3 circuit boards:
1. Power supply board

2. Backlight board

3. Logic board

So you're trouble is likely coming from the logic board. So that's where I would start. Since you have several of these around, you do have the luxury of swapping modules from a known good set into this one to track the issue down.

similost · #3 09-21-2009, 08:47 AM

No, no one has touched them.. only me... I could try other boards, but I don't think the powers that be would be real happy with me taking a working unit apart..

Seeing as there are only 3 boards, there is power, and backlight.. yep.. I would imagine the logic board.. but this is all new stuff to me.. I had no idea that was how little was in them.

*zenithfan1* · #4 09-21-2009, 11:53 AM

Quote:

Originally Posted by similost

I had no idea that was how little was in them.

Makes you think twice about what they cost and what they did cost a few years ago huh? A big rip off IMO. The picture is nice but geez they could have made them much more affordable. I know squat about these, sorry I can't help. I hope you figure it out. Logic board makes the most sense though.....Good luck!
P.S.
That first pic looks cool, if it can't be fixed just tell everyone it's "modern art" LOL.

andy · #5 09-21-2009, 12:25 PM

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Zenith26kc20 · #6 09-21-2009, 12:29 PM

From those I have serviced in the past, it's the logic board. Shopjimmy.com is where I usually get the parts. Also, check (before you order any parts) any ribbon connectors. These can get oxidized and cause a variety of sysptoms.

similost · #7 09-21-2009, 12:32 PM

Thanks all.. I like the modern art idea..

It is all inputs... I've been doing some reading around and found others with this same symptom out there, and appears there may be 4 caps on the logic board that need to be replaced. All 100uf and 50v... Sounds like it may be an easy fix.

*zenithfan1* · #8 09-21-2009, 01:58 PM

Fingers are crossed, that would be almost too easy. I hope that's what's wrong, a shame to have to junk something so new. (or part out for the others)

RDusel · #9 09-21-2009, 03:14 PM

Those caps sound like the culprit. Send a pic of the logic board when you open it up, I would love to see it.
We lose a Dell motherboard every month at the office, look for the bulge, change a few caps and it's back in service.
Also very interesting in that the computers do the same thing your monitor did, work fine with bad caps until you power them down and then they never come back on.
Rob

radiotvnut · #10 09-21-2009, 03:45 PM

I hope it works out for you. The local TV shop that I get stuff from says he fixes many LCD's by changing bad caps. I haven't gotten that lucky with the ones that I attempted to fix.

freakaftr8 · #11 09-21-2009, 04:04 PM

Had aan issue like this with a 21" LCD widescreen monitor a few months ago. Turned out to be bad caps.

LCD products seem to be extremely hard on lytics....

That cap (or caps) have probably been bad for a while now but functioning.. The powerdown and powerup probably did them in, meaning they were asked to take the inital ramp up charge at startup and they just liost the ability to do so but can run stable still at an everyday use as long as it waqsn't turned off.

radiotvnut · #12 09-21-2009, 04:36 PM

And it don't help much when they use low quality caps.

MRX37 · #13 09-21-2009, 05:36 PM

LCD is fine. Problem lies in whatever board is driving the LCD.

Findm-Keepm · #14 09-21-2009, 05:37 PM

Not for LCD sets, but this Plasma Display Manual does give some "If you get this picture, look here for the fault" help for Plasma sets:

http://www.talonix.com/images/46in_P...ice_Manual.pdf

Some Korean company, either Samsung or LG produced it, I believe.

I've got one somewhere from Panasonic that pertains to LCD sets and picture-to-fault finding. I'll see if I can find it and post it. It was free at one of Panasonic's Service Training Seminars I attended. Panasonic demonstrated the power consumption of Plasma sets versus "older tube designs" by comparing the smallish plasma set vs a Zenith hybrid set. The plasma set used 20% more power than the Zenith, I recall.

Cheers,

Findm-Keepm · #15 09-22-2009, 10:36 PM

I found several Sharp Aquos service manuals on scribd.com - search on sharp aquos and you'll find them. Login credentials are free, and you can download the pdf once logged in.

Hope this helps - cheers!