Samsung forum: Samsung LCD TV LN-T5265F Black Screen Diagnosis Help

in case anyone else stumbles across this thread, here is some more info about the faulty capacitors.
-They are branded "Samwha", which apparently is a company that took over Samsung capacitor manufacturing in 2002.
-The failed capacitors are series "WB". The current Samwha website indicates that this series was "obsoleted in 1999" (http://www.samwha.com/electric/templatedirs/guest/pro_discon23.html)
Exactly what "obsoleted in 1999" means isn't clear, but it seems strange that they were used on a TV manufactured in 2007. I found a datasheet for the series here: http://www.abcd-e.cn/abcd-e/www/a/products/capacitors/aluminum_electrolytic_capacitors/samwha/samwha_2006/wb.pdf They are described as "ultra low impedance" and have a high ripple current tolerance. The Samwha website identifies the "MK" series as their current replacement for "WB". http://www.samwha.com/electric/templatedirs/guest/product23.html

I found an almost exact specification match with the Nippon Chemi-Con KZE series http://www.chemi-con.com/files/KZE.pdf , specifically EKZE100ELL102MJ16S. I ended up ordering this instead of the KY series I linked to in my previous post.

I have since read on many posts that people have been successfully picking up off-the-shelf capacitors at Radio Shack or Fry's that are slightly over-rated, i.e. 1000uF, 16V capacitors apparently provide some additional ripple-current capacity than the 10V equivalent. Not being an electrical engineer, I'm not sure if there are any downsides to that approach, but fyi I had a look in Fry's this morning and they stock a 1000uF, 16V "ITE" capacitor for $1.92 which works out to almost the same total cost as I'm paying for 5 capacitors plus shipping from "mouser.com" (I decided to use Mouser instead of Digikey when I realized Mouser's Dallas-area distribution center is about 30 miles away, so UPS is next day for me).

fyi... while googling this problem I came across perhaps 5 or 6 posts from users with similar symptoms who reported that the first occurrence of the problem coincided with some heavy rain or high humidity. Same thing happened to me. House had been sealed up all summer in air conditioning mode, so indoor humidity had been low and consistent. But we had some cool weather so I opened up all the windows, and then we had heavy rain, causing the indoor humidity to go way up. The TV stopped working within a few hours of the rain starting. My theory -- the blown capacitors are no longer sealed, so the high humidity can readily get inside, causing the already-degraded capacitors to perform even worse.

have posted some photos of the power supply board and the capacitors for reference
http://s625.photobucket.com/albums/tt331/andrewsb62/samsung%20lcd%20bad%20capacitors/

We came home today, turned on our Samsung 46" LCD tv, no picture, just sound. We contacted Samsung who in turn had a certified repair service call us. The service guy was extremely rude. He wanted to charge mileage, even though we are in the same city, plus $35 fee for us being out of his area, and set fee for the call. That is without even looking at the tv. I searched the internet and found this forum and your post. We have our tv working and saved hundreds of dollars. My husband and I thank you, thank you, thank you!!!
My husband went to Radio Shack to by capacitors. He was surprised when the salesman asked him if we were repairing a LCD tv. The salesman said a man had been in that store the night before buying the same thing. Samsung needs to pay you!

If you can't do the soldering yourself, almost any person who has ever used a soldering iron could do the job. I read one post where a guy bought the caps at Radio Shack, and paid a kid behind the cash register $10 cash to do the soldering. If you don't know someone like that, you can either find an electronics repair shop to do the repair for you (check the yellow pages & call for a quote; some shops won't do little jobs like this), or you could replace the whole power supply board. They are available on the net for less than list price. eg. at http://www.encompassparts.com/ the board for my TV is about $105 vs.about $170 from Samsung. Installation takes just a few minutes. Philips screwdriver is the only tool required. In either case, I'd suggest you open the TV yourself to remove the power supply board; once you see the board, you'll know whether it has blown capacitors or not. If you see bad caps, you can be confident that either fixing or replacing the board should work. If you don't see bad caps, then I'd still suspect the power supply board but would order a new one from a place with a reasonable return policy so if you're wrong about the diagnosis, you'll be able to return it and hopefully only lose shipping costs.

those bulging capacitors are definitely a problem, and very likely your only problem. That $65 board sounds like a good deal.

No all i could find were used and recycled boards. I called up the company and asked what a recycled board was and they told me it was boards from returned TV's that have been tested to work at the level of the original. To be honest I'm actually expecting it to break sooner or later. its just that money is very tight for me and the cheapest i could find someone to look at it was $75 and he said that he wouldn't replace the capacitors he would only find a new board and i would still have to pay for parts and labor. So i figured paying $65 for a whole new board would be a little cheaper and i also get a 30 day money back warranty on the part so if it doesn't fix the problem I'm only out $10 in shipping. So even though it probably wont be a permanent fix, it might get me another 6-12 months while i try and find someone to replace the capacitors on the original board. I thought it made sense at the time......I hope i was right :/

the fact that the new board fixed the problem, even temporarily, seems to suggest that the board is indeed the source of the problem, but why it would then fail after a couple of days is a mystery. If it was a recycled board, maybe there was some other problem with it, or maybe it wasn't repaired properly. So on that theory, you could order another power supply board, and if that works then return the first one under your 30 day warranty. The risk is that the problem is something different, in which case you could end up with two power boards and no solution, but between the bulging caps on the original board, and the temporary fix when you replaced it, I'm still thinking the power supply is very likely the issue.

What is the board model #? I searched your TV model number and came up with a couple of possibilities like BN44-00192B and BN44-00208B, each for about $50 new.
https://www.encompassparts.com/webwiz/wwiz.asp?wwizmstr=WEB.SEARCH&mres=1&mrpn=SMGLN26A330J1DXZA

the one i ordered was bn44-00192b. I got it from partstore.com. i just got another tv today, but would still love to fix my samsung. i think i will return the recycled board and try another one. : /

i am defiantly going to try again. and will try that site if i can get a NEW board over a recycled one. Thank you. I'll keep ya up to date on how it goes. THANKS AGAIN

Thank you so much for the information on repairing my tv. I was able to get a guy from my church to replace the capcatiors and the tv now works again.

yes, in my case replacing the caps was all that was required, but I could see three visibly bad capacitors so I felt pretty confident that would be the problem. If you don't see bad capacitors, then it is hard to guess whether they might be the source of your problem or not. If you are comfortable with a soldering iron, changing the caps is quick and cheap, so you don't have much to lose by trying.

roughly nine months have passed since I started this thread, but after initial success fixing the TV by replacing capacitors, I have had it fail two more times, so I thought I would post an update.
When the first repeat-failure happened, I inspected the power supply board, and could see no sign of problems with the capacitors that I had previously replaced. But I replaced them again anyway, and still the TV wouldn't start. So I ordered a brand new power supply board, and it worked first time. So I figured my repaired power supply board must have had some other hidden problem. I stuffed it in a closet.
A couple of months passed, and then the TV failed again, with exactly the same symptoms. So I ordered a new power supply board again, but this time, the new board didn't help. So I started to hunt around for another cause of the problem, and zeroed in on the inverter boards, of which there are four. Every time I turned on the TV, there was a buzzing sound for a few seconds, and by listening closely with the back off the TV I was able to determine that the buzz was coming from the lower right board, part INV52B24A (RL). Then I had a hunch -- we've probably all seen fluorescent lights have a tough time starting when they are cold. Well it seemed to me like the inverter was trying to start the fluorescent backlight and not quite getting it going. So following my crazy hunch I grabbed a hair dryer and started to heat up the entire area around the inverter boards, thinking that if I could get the fluorescent tubes warm, they might start up. Crazy? Well, it worked! After maybe two minutes of heating, the TV started up normally. The I powered down and left the TV off overnight. The next morning, it wouldn't start up again. So again, I grabbed the hair dryer and started heating, and again, it worked after a few minutes. Interestingly though, when the TV did start, there was still quite a bit of buzzing coming from the RL inverter board, but not any of the others. Then I got really close to the board and looked at all the transformers, and was amazed to see across one of the transformer casings, exactly where the buzz was coming from, what appeared to be a light scorch mark and a tiny crack. Could this be the problem? I decided to try to replace that board, and quickly found that this part doesn't appear to be sold by Samsung as a separate part, however I found a used board on "ShopJimmy" and decided to give it a shot. Board arrived a few days later, and upon installation, the TV immediately worked, with no hair dryer, and no buzz whatsoever. I turned it off for a couple of days to make sure it was completely cold, and it powered back up without problem. Then I decided to swap out the new power supply board with my original, repaired power supply board, and that worked too.
The TV has now worked fine for two weeks with the new inverter board. It's hard to know how the the power supply capacitor problem and the inverter problem are linked... maybe the original capacitor failure caused damage to the inverter transformer. Or maybe they are completely unrelated failures that coincidentally had the same symptoms. In any event, the TV works again, at least for now.

I have a 52" LCD Samsung and I'm having the on/off problem. Randomly the TV will turn off and back on. Doesn't appear to be heat dependant as it's happend in a variety of intervals and conditions. This just started a 3 or 4 days ago. I have pulled the power circuit board (BN44-00201A) and all the caps look fine. The board is stuffed with Samwha caps and from what I've read they can be problematic. I'm going to change out the 16V 1000uf caps with some Sanyo 25V caps and see what happens. Maybe because this just started the caps aren't in bad enough shape to start bulging. I'll let you know what happens.