Fixing an LCD TV power supply

[mrSHEiK124]

I have a no name LCD TV, and a college student's disposable income. My TV is acting like it has bad caps - actually I opened it, and it has bad caps. It turns in 1 in 20 times, and when it does it takes 15 minutes for the picture to come on (usually just turns off). Sometimes it'll stay on, and work - as long as it's on.

Is there anything in here that can kill me? I know CRTs had something that could shock you well after they were unplugged, but I've never messed with or tried fixing an LCD. It's been unplugged (and open) for about an hour now.

 

[PottedMeat]

I have a no name LCD TV, and a college student's disposable income. My TV is acting like it has bad caps - actually I opened it, and it has bad caps. It turns in 1 in 20 times, and when it does it takes 15 minutes for the picture to come on (usually just turns off). Sometimes it'll stay on, and work - as long as it's on.

Is there anything in here that can kill me? I know CRTs had something that could shock you well after they were unplugged, but I've never messed with or tried fixing an LCD. It's been unplugged (and open) for about an hour now.

As long as it's unplugged, probably not. If the high voltage caps are still charged and you accidentally run your fingers across them it'll hurt but that's about it.


I've never seen bad high voltage caps ( 160VDC+ ) on a power supply, they've always been on the low side ( they say 6.3V or 16V rated working voltage on the side ).

 

[dwell]

Unplug, lay your screwdriver across the leads of the large caps to discharge them, and don't ever touch the leads of the big caps with bare hands.

 

[mrSHEiK124]

As long as it's unplugged, probably not. If the high voltage caps are still charged and you accidentally run your fingers across them it'll hurt but that's about it.

Excuse my ignorance, but the ones that look like this?

http://imgs.tootoo.com/f9/e5/f9e5e083a0122870ba057da718274897.jpg

Or the cylindrical ones? I can't exactly read all the voltages (physically obstructed) but I already set my finger down flat on a couple of those to see if they were bulging or not. They're so cheap, I'm just going to replace all of them. If one went bad they all can right?

 

[oppie1]

I had to replace some caps in my vizio plasma a few months ago. Itnwould turn on, then shut off. Would take a few cycles before it would finally stay on. Was a pretty easy fix, with the exception of the 40 some-odd screws I had to take out to get to the power supply. Been running like a champ ever since

 

[PottedMeat]

Excuse my ignorance, but the ones that look like this?

http://imgs.tootoo.com/f9/e5/f9e5e083a0122870ba057da718274897.jpg

Or the cylindrical ones? I can't exactly read all the voltages (physically obstructed) but I already set my finger down flat on a couple of those to see if they were bulging or not. They're so cheap, I'm just going to replace all of them. If one went bad they all can right?

uh the blue ones you listed are little high voltage caps between the inverter and the fluorescent tubes - those can go bad sometimes.

i thought you were talking about the aluminum cylinders like this:
http://www.badcaps.net/images/caps/kt7/kt3.html


which ones actually look bad?

 

[SparkyJJO]

Fixing LCD TV power supplies is pretty easy.

I recommend getting parts from Digikey, Panasonic FM or FC series caps are good.

 

[dwell]

Excuse my ignorance, but the ones that look like this?

http://imgs.tootoo.com/f9/e5/f9e5e083a0122870ba057da718274897.jpg

Or the cylindrical ones? I can't exactly read all the voltages (physically obstructed) but I already set my finger down flat on a couple of those to see if they were bulging or not. They're so cheap, I'm just going to replace all of them. If one went bad they all can right?

The electrolytic "drum" caps are the ones that go bad as PottedMeat pointed out. The polyester film or ceramic disc caps probably are not bad. Look for the bulging drums. Be careful around any listed as 300v or above.

 

[alfa147x]

Damn it! I regret not grabbing a large LCD next to the dumpster last week :\

 

[Bignate603]

Damn it! I regret not grabbing a large LCD next to the dumpster last week :\

Every once and a while I look at craigslist to see if there's a broken LCD TV for sale that might have broken caps.

 

[SparkyJJO]

Every once and a while I look at craigslist to see if there's a broken LCD TV for sale that might have broken caps.

Same. I'd love to pick up something like a 36+" for 50 bucks, put a couple hours and $20 worth of parts in it, and have a decent TV

 

[alfa147x]

Every once and a while I look at craigslist to see if there's a broken LCD TV for sale that might have broken caps.

Good idea. Thanks!

 

[mrSHEiK124]

http://pics.bbzzdd.com/users/sheik124/IMG_3076.JPG
Power supply board, new caps I ordered online in a set ( http://www.ccl-la.com/blog/index.php/solving-emprex-hd-3202-power-problems/ ) Now I know to go for Panasonics from DigiKey and know that I can identify them by reading them I hope the Nichinons they sent me are good.

http://pics.bbzzdd.com/users/sheik124/IMG_3078.JPG
Two totally busted 10V caps, a couple of bulging 16V. Ended up replacing them all since I was already in there. I've heard loud "pop"s come out of my TV before, was it the sound of cheap caps going boom?

http://pics.bbzzdd.com/users/sheik124/IMG_3081.JPG
First Nichinon cap in - that's what you get for using a power supply made by this guy

http://pics.bbzzdd.com/users/sheik124/IMG_3082.JPG
All new caps.

http://pics.bbzzdd.com/users/sheik124/IMG_3084.JPG
Pieces of shit. CapXon?


Click it.