or Connect
AVS › AVS Forum › Display Devices › LCD Flat Panel Displays › Samsung cap failures?
New Posts  All Forums:Forum Nav:

Samsung cap failures? - Page 3

post #61 of 84
Excellent articles and well worth the read. What needs to be understood is that when a capacitor housing is “bulging” is it because the dielectric barrier has been compromised and it is now functioning as a resistor which is why the component is now heating up. This problem has been occurring long before the high-frequency switching power supplies were developed. A capacitor that “dries out” becomes a useless component in the circuit. It is as if it did not even exist.

Are there factors in capacitor design that must be considered when working with higher frequencies? Of course there is. Never-the-less, it is important to consider the peak operating voltage when a designing a capacitor in a circuit. It is also important to properly select the dielectric composition material. What amazes me is that what is going on right now with the Samsung capacitor issue has been going on for the 30+ years I have been involved in the electronics industry. They may have messed up on their design specs or they may have received a faulty batch of capacitors from their vendor. The cat is out of the bag and they are going to have to deal with it accordingly.
post #62 of 84
Originally Posted by display veteran View Post

Capacitors are very comfortable with high frequency ripple when it comes to line filtering.

Originally Posted by display veteran View Post

Are there factors in capacitor design that must be considered when working with higher frequencies? Of course there is.

yeah... it is amazing what a bit of reading could do....

who knows.... in the future you may learn to accept my facts in the first place without trying to prove that you know something I don't by negating them; you'll save time and further embarrassment...

post #63 of 84
Originally Posted by mcw53 View Post

I believe my LN46A750 just "capped out" after 26 months. Purchased from Amazon on 06/23/2008, died 08/20/2010. No extended warranty. Has anybody been able to get Samsung to repair this defect out of warranty?

EDIT: I created a repair ticket and called Samsung. They are going to pay for the repair as a one-time "Courtesy Repair". Now that is customer service!

Called Samsung Friday night. Contacted by the local repair tech Monday. Power supply board with upgraded capacitors installed today (Tuesday). Although I am dissapointed that such a phenominal television had this weak link, I am a satisfied Samsung customer. Looks like Samsung is finally stepping up and taking ownership of this problem ... or maybe I just got lucky.
post #64 of 84
Originally Posted by Extreme_Boky View Post

yeah... it is amazing what a bit of reading could do....

who knows.... in the future you may learn to accept my facts in the first place without trying to prove that you know something I don't by negating them; you'll save time and further embarrassment...


This guy looks forward to reading my posts and attacking me. It gives him a purpose in life. If I was not so good at what I do I would probably be offended and post personal attacks on him too.
post #65 of 84
I was visiting my parents out of state who own a Samsung LN46A550 they bought 7/2008, it has been having a very intermittent problem where screen on right half goes dark and gets lines on it, not sure what to make of this, was down there this weekend and took some pics with my cell phone, am curious what others make of it.

They say it almost always does this when powering up the TV, often only lasts for 15-30 seconds then intermittently comes and goes while watching TV.

They're using a Denon A/V receiver where source devices are plugged into with HDMI then output HDMI to the TV. To simplify things I connected their BluRay player directly to the TV via HDMI on the side HDMI port (different port than the one the Denon is connected to) but still got same problem so definitely TV, not loose HDMI connection or some such. Any thoughts??

They don't have an extended warranty. My parents concern is if they have Samsung come out they'll charge them $100 whether any work is done or not and that the repair will probably be high say $400+ when you can buy a brand new comparable Samsung for $800 and then get an inexpensive extended warranty on it from somewhere like Square Trade.

post #66 of 84
I don't like how they are giving people the runaround on this issue.. makes me wish I would have bought a sharp after reading all this, but it seems like an issue that's easily fixable assuming they haven't fixed it already. It would be silly if they haven't, since it would cost them much more money in the long run then spending an extra 2 dollars now since the problem is well documented.

Nobody has really confirmed the 2010 models are all fixed, though I'm assuming they are now. They better be! I'll probably have it happen to the set I just sold to my mother at some point. Luckily I know enough about the problem that I'll either demand they replace the whole board, or order the caps myself and demand they send someone to change them for me.
post #67 of 84
So I've been reading the forums and it seems some people are buying 1000uf 35v and others are buying 2200uf 35v.

My TV went bad a year ago, Samsung fixed it and now it's dying again (took 8 tries to power on this morning).

I can't open it up to see which ones are bad until I get home, but if I were to go to Radio Shack should I just get some of both before going home to replace them? Or should I wait to open it and see if I can divine which ones are bulging?

post #68 of 84
Originally Posted by Doug0915 View Post

Or should I wait to open it and see if I can divine which ones are bulging?

Not only better rating, but u gotta be sure the new cap will be able to fit in the space alloted, physically, so I would just asses the situation first.

I would personally look for better rating all around, definitely higher voltage handling capacity than before, but lower leakage (many time labeled as PREMIUM), and higher temperature (most caps are rated for 85c, but the better ones are rated for 105c).
post #69 of 84
I had what I thought was a cap failure but now appears to be a resistor of some type. It's a BN44-00202A power supply (IP-271135) for a LN46A650 but what fried for me was the resistor (?) at position DP806.

Attached is an image I grabbed via Google indicating position. Does anyone know what it is? I'd like to try to get one at Radio Shack but the one currently on my board is completely fried so I can't make out any markings.

I'm probably going to go ahead and change the caps too if they turn out to be rated 10v.

post #70 of 84
That’s a diode - not a resistor, and it does not look completely fried, it looks okay. Markings are usually very faint anyway....

It looks like fast switching diode, so any fast switching diode of 400V or more, and around 5A or more will do...

Even if it is not a fast switching diode, replacing it with a fast switching diode will not do any harm in any way.

post #71 of 84
Forgive me for bumping this old thread but I don't really know where else to turn. My wonderfully convincing wife managed to get Samsung to send out a tech to diagnose my LN46A550 after it began to exhibit the same click-click-click issue that seems to be quite widespread. To my surprise, the technician who came out actually replaced two capacitors (CM852, CM853) as instructed by Samsung. Sadly, this did not fix the problem and my three year old TV still won't turn on. I've inspected the power supply completely and all of the capacitors look fine. Are there any other alternatives I can look into? I refuse to pay anyone more money to have a television that works. If I can't fix it myself then Samsung can suck it.

Any suggestions?
post #72 of 84
He replaced only two capacitors. Sounds like others may also be damaged even tho they look OK. If I were you, I'd call Samsung back, because I've had two LNT's with the problem and both times Samsung had the tech replace the entire power board, not just some capacitors. I'd bet your repair guy got a new power board and was supposed to put it into your tv, not just replace a few capacitors. Call Samsung back and just tell them what was done and that the tv still won't turn on and that you want a new power board.
post #73 of 84
My 46A650 bit the dust a few months ago. Had the clicking, and then finally it wouldnt turn on at all. I was looking for an excuse to upgrade, so I went ahead and bought a new set.

Finally got bored enough this weekend to crack open the set. Saw two bulging caps. I brought the board to work, we had caps of the same type and soldered the new ones into place.

Took it home and the set fired right up. Very simple repair. Now I just need to figure out what I want to do with the set.
post #74 of 84
Lots of funny explanations on 'why' in this thread... Pretty sad as well

Capacitor failure is due to a mechanical failure of the dielectric or electrical pathway. You can have a dried out cap that works perfectly fine as long as there are no circumstances that cause the aluminum oxide layer to degrade. Electrolyte creates the oxide layer and this is THE ONLY THING IT IS USED FOR. Heat evaporates the electrolyte & heat dissipation is caused by either ESR or dielectric breakdown (leakage). Exceeding ripple current rating or exceeding caps dielectric strength rating will cause power to be dissipated inside the cap which will cause the electrolyte to evaporate and can lead to dielectric failure or current path failure.

When caps vent like that after a long time, it is due to ripple current exceeding spec which causes heating across the ESR which causes a slow breakdown/drying up of electrolyte which causes the aluminum oxide layer to break down which causes the cap to dissipate more real power internally as it becomes more & more shorted. The electrolyte is ONLY there to facilitate the insulating aluminum oxide layer formation and maintenance which is the dielectric separating the two electrodes. With dried out electrolyte in the fiber layer, the caps can not self heal (Reform aluminum oxide) which causes shorting & increased power dissipation. I design SMPS, the details are much more nitty gritty than this, but basically this is what happens. Electrolyte doesnt care about voltage & the electrolyte isnt what is causing the issue. Exceeding the caps rated voltage causes more 'break through' of the aluminum oxide layer than what can be self repaired by the electrolyte's oxidizing effect so more and more current flows through the cap in phase with the voltage wave so power is dissipated which dries out the electrolyte even more and the downward spiral continues. The FULL explanation of everything that happens would take a page or two, but in a nutshell this is it.

Ripple current rating is directly related to ESR. Low ESR caps cost more money. Chinese cap manufacturers have a lot to be desired when it comes to quality & accuracy of their product and specs. They seam to like to change things to make things cheaper while not telling their customers...

Whether the specified caps were changed by the chinese manufacturer after qualification by Samsung's testing, or if Samsung specified caps that were not up to spec in the first place is unknown. But If you dont want this to happen again, look for a cap with low ESR and a high ripple current rating and spec a working voltage that is 20% higher than actual needs.
post #75 of 84
My LN46A650A1F went out last April and was "repaired" under the 1 time free capacitor replacement after playing the shell game with them on the phone. I don't know how many caps the tech replaced, but yesterday morning the issue began again. I've sent a lengthy e-mail to Samsung tech support and am eagerly awaiting their response. This issue in my opinion was not sufficiently addressed by the company when it came to light and is obviously snowballing into a real mess for them. This boat is sinking from a thousand leaks and they're running out of duct tape long after their chance for dry dock has passed. I wonder who the "Captain" was who made that decision?

I'll post the outcome.


As expected, they took a couple of days to think about it, and sent back a carefully worded response which basically serves to exhonerate them from all responsibility in the matter. They recommended me to schedule their authorized tech to come out and repair it at my cost. If THEY can't fix it for free the first time, why should I pay them to not fix it the second time? They obviously only replace caps on a visual inspection basis, as proved by the many posts here that say how fast they were. They did not use any test equipment either on the caps or any other component on the board which might have suffered collateral damage. Is this all it takes to be an authorized Samsung tech? Visual inspection? Back in the day when I worked in an A/V repair shop (back when we didn't just throw things away and buy a new one, heck we even repaired little personal tape decks!) we used multimeters, signal injectors, oscilloscopes and various other devices before we called it a repair! We tested other local components to make sure they were not damaged by the failing part or were the cause of it! And we always ran a TV for a day to make sure it was working! Clearly, things are much easier for a tech these days. I must be in the wrong line of business.
post #76 of 84
Had the day off for some medical appointments in the morning, so I used the afternoon to take the Sammy off the wall and see what's cookin'. The only chance I've had without the kid's being home to get in the way.
So I got it face down on the carpet and removed the back panel and RF shield, and what do you think I saw? The "Authorized Samsung Tech" had replaced the two 16v 1000uf caps that "looked" bad, and there, right next to them were the two 25v 1000uf caps that he DIDN'T replace because they DIDN'T "look" bad, which of course were now all puffed up with all the magic smoke gone from them!
I called around and found a local shop that had some quality replacements and went ahead and did the fix myself. Not like I had anything else to do, I mean, who doesn't have lots of free time on there hands in December? Fortunately every thing worked out, the set fired up just fine and I had it back together before my wife got home with the kids.
But you know, every tech I talked to today said the same things. Samsungs are their top service calls. Whenever they have a "cap job" they always replace ALL FOUR of the caps, regardless of how they appear because they know they are going to fail! Why didn't Samsung do that? Do they give the "Authorized Samsung Techs" a wink and a nod, knowing there will be future customer paid business with the other caps? It really makes you wonder what their logic was when they decided to handle this matter in such a shady way. The caps don't cost them squat! It's sending someone out that costs them! Why would you even take the chance? it's only going to turn into a bigger headache and more dissatisfied customers! A few years ago you might have gotten away with it, back when it was mostly people with money to burn that had big flat screens, and they were more likely to write it off when things went south after the warranty expired. But now you see them in homes of every demographic. Believe me, I know. My job takes me inside homes in every type of neighborhood. Alot of these people bought them when "Uncle George" sent them their tax incentives, and those who weren't so lucky had to scrimp and save to put that "Big Ticket Altar to the Consumer Gods" on the wall. They will not take it so lightly when a couple thousand dollars just evaporates before their eyes! Not in this economic climate!
So do yourself a favor. If you get the "Free one time service", make sure you demand that they replace ALL FOUR 1000uf CAPS! Print this out and let them read it if they balk. Oh, and ask your local INDEPENDANT repair shop what their number one repair brand is, and the brand they repair the least, just on the outside chance you have to buy a new one.
I will put money on which brand it won't be!
post #77 of 84
I have two LNTs which both required cap replacement. The shop which serviced our tvs brought out two new entire power boards and replaced the boards and took the old ones with them. I was there during the repairs and watched. They had no caps with them, so it was obvious they were authorized to replace the whole board.

So possibly, rather than bash Samsung, who is still fixing this problem out of warranty, you might want to question the integrity of your repair shop. If they get reimbursement for a board replacement but just replace a few caps, they make a lot more on the call.

I'm sure I'm not the only one who got a proper replacement and bashing Samsung is really not right in this matter. They made a sub par decision with the original board but at least stepped up to fix it, free.

Maybe you should be complaining to your repair place for their lousy repair.
post #78 of 84
What "repair place" ? It was "repaired" by an authorized Samsung tech who was sent to my house. Samsung knew he only replaced two caps and stood behind it, claiming all defective parts had been replaced.
Samsung has not "stepped up". They have never made any official recognition that there was any manufacturing defect. During my initial phone contacts with Samsung technical support everyone I talked to claimed no knowledge of any widespread cap failures unless I pushed the issue and told them I had already read up on it. I would then be handed off to someone else and have to go through the same conversation. When I finally got the end of the line and was making an appointment with the local service, I was told I had to call back to the main support line because they hadn't authorized it for them to make a free repair, and they would be charging me for the visit. It was quite obvious to me that if a person had no knowledge of any of this they would NOT be getting a free repair. I have no idea who the local repair service was other than the fact that they came from a city an hour away, they left no documentation. But they were who Samsung sent and Samsung did not question their "repair", but stood behind them and offered me no consideration when I questioned the repair in a polite and logical manner, after I made them aware of the fact that I am more than somewhat educated in the field of consumer electronics repair.
You were obviously fortunate in the fact that whoever repaired your units felt that Samsung should be completely responsible for the proper and complete repair of the failure. I, on the other hand feel that I have been given the run around from beginning to end. And at this point I can have no more respect for them until they make a public admission to the defects and start a warranty campaign to rectify the affected devices that is NOT hidden from view, as well as an apology and reimbursement to the shoddy treatment of customers such as myself and any of the others here or anywhere else who were either charged for the service or had incomplete repairs performed.
After reading through this entire thread and speaking to local repair techs it is quite obvious that Samsung has issued no uniform guidelines in the repair of these particular failures and left it completely up to the local authorized service to do what they feel they can get away with. Back in April I was in the same camp as you. I disregarded the shell game I had to play on the phone and felt that I had been taken care of. Unfortunately since then they have written me off and prefer to watch their bottom line over giving good customer service. I'm sorry, but regardless of how much I like this TV, Samsung has shown me little appreciation in my choice of their product and done nothing to promote my loyalty.
post #79 of 84
I just inherited a LN46A650 from a client. It turns on no image displayed though. No menu, no ant races on antenna just grey glow from backlight. Caps seem to be the common fail point and I am willing to throw a few buck into this. So there are 6 caps in corner of power supply I need to replace.
(2) 10v 100uf
(2) 25v 470uf
(2) 25v 1000uf
I am good with a soldering iron. Not so much in any of the other witchcraft that makes the world go round. So what value caps should I replace these with? If it was your set and you didn't to revisit the issue in a year or two. Thanks. Sorry if this was answered above. I read too much stuff and now my brain in going to explode. Don't really care about the why. Just looking for an answer a big dumb ogre can use. Thanks
post #80 of 84

Check the link for all the info you will need to do the repair:

post #81 of 84
Bad caps or just shoddy quality in general is a problem that will persist as long as people value low purchase cost over quality. Most consumers are of low or average intelligence, and cannot be taught the finer details of engineering. They just look at cost. A TV is a TV is a TV, right? they say. No, it isnt, but you cant explain it to them, because they cant understand and arent interested anyway.

The ever pragmatic asians have learned this, and delivers products that are tailored to the average american customers purchase desire. Just avoid brands/product lines that cater to joe average.
post #82 of 84
Yes but bad caps have shown up in samsungs very expensive 8500 series.
post #83 of 84
Bad Caps are pretty non-discriminating. We have them show up frequently on the control board of certain GE refrigerators, too.
post #84 of 84
Samsung saved a couple of bucks using cheap caps. It costs users a lot to replace them. It would have been a great set if the proper caps were used.
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: LCD Flat Panel Displays
AVS › AVS Forum › Display Devices › LCD Flat Panel Displays › Samsung cap failures?