Samsung 46" LCD slow death

[c5golfguy]

Bought this 120hz 1080p Samsung 46" LCD about 23 months ago. Had picked it up at Circuit City on a steal thanks to a deal I found on www.slickdeals.net. Needless to say, the warranty was up. Last Wed. the tv started clicking and having an issue on turning on. You could hear a switching sound, that sounded like a relay was clicking. Started doing some research and found out that the capacitors were to blame. So, here is a good documented process of replacing the capacitors. Hope ya'll could use this sometime in the future for your flat screens you got in your home or garages.

Took a picture of where everything went in case I needed it.

Here, you can see the caps bulging. These caps were 2200uF, 10v and 105c in temp. I upgraded to 16volt caps so I don't have this problem again, since the tv operate at 13.1volts.

Another of the caps pointed out by the arrows.

New caps installed. You can see the difference in quality of the new caps compared to the old blue crappy caps.

Another picture of the finished product.

Full picture of the circuit board.

Finished solder job. The negative side of one of the caps solder job wasn't that great of a job. It's somewhat boogered up in my opinion, but it works.

The board mounted back into the tv and ready for the cover to be put back on and try it out.

She's alive and working great. No more problems starting up.

 

[ddawg16]

Watching Glenn Beck? That could be construed as a political statement....

Don't worry...I've got your back....

Thanks for the post....good info.....

And I do agree.....caps are one of the weak points in most electroics....usually the first item to go.....if you see a semi-conductor burned up.....good chance a cap helped it burn....

 

[alberto]

Wow, I never would have figured out what to fix. Great job. Thanks for posting, learn something new every day.

Alberto

 

[TRC51]

Definitely great info. Got an LNT5271 in the basement... but not much time on it. Do you think it was extended use that gave it trouble... room conditions.... solar bursts... wobble in the earth axis...

... or just a fluke.

 

[doug.j]

Definitely great info. Got an LNT5271 in the basement... but not much time on it. Do you think it was extended use that gave it trouble... room conditions.... solar bursts... wobble in the earth axis...

... or just a fluke.

http://en.wikipedia.org/wiki/Capacitor_plague

 

[c5golfguy]

Definitely great info. Got an LNT5271 in the basement... but not much time on it. Do you think it was extended use that gave it trouble... room conditions.... solar bursts... wobble in the earth axis...

... or just a fluke.

yeah.. we got the 4671. With less then 2 years on her.. not sure what the deal is with our particular tv. Researching the net, I found several threads/web pages all over the world and evidently its a serious problem that Samsung is not taking responsibility for. They showcased how to fix the problem and I just went from there. Wife is happy... she didn't want to buy another tv right now.

 

[CraigFL]

In my business, we see the capacitor problem often along with a problem most people call "cold solder joints". Normally, a solder joint that is not heated enough for the solder to flow will be grainy and lumpy and seen as "cold". In our findings, some properly made solder joints look grainy and cracks may form radially around the wire lead causing a bad/intermittant connection over time. In most cases, just resoldering to form a bright, silvery connection will solve the problem.

 

[Falcon67]

Also when soldering on a board, you have to watch the heat or you take the chance of lifting the trace. Maybe they put a 10 english V capacitor in there, expecting it to run in a 13.1 metric V circuit?

 

[rieferman]

During a repair such as the one you performed, are ESD issues a concern?

 

[scofo]

Nice repair. The TV probably attempted suicide after seeing a grown man cry. :]

 

[Falcon67]

During a repair such as the one you performed, are ESD issues a concern?

You should always be careful there, but the board looks like it's more hard parts than any real ESD sensitive items.

Just noticed - he has the exact same kitchen table that we do (wood w/ white tile).

 

[CraigFL]

...Just noticed - he has the exact same kitchen table that we do (wood w/ white tile).

We have one of those too! Is there something about garages and white tile tables??


As to the soldering-- You need to be careful on some of the new printed circuit board because they are multi-layer with plated thru holes. Sometimes wire leads need the solder to flow thru the multi-layers and sometimes holes are just connected thru the layers and applying heat will disrupt the connection

 

[Tech Guy]

As a tech, I can appreciate how you documented the problems and the repair. Nice job ! another thought, could it also be old dried up dielectric in the capacitors due to them sitting on the shelf too long ? Voltage of original cap was probably your main issue though.

 

[sgrammel]

You had to explain this? .Like we all don't already know how to do such a repair

 

[Possum]

Nice repair. The TV probably attempted suicide after seeing a grown man cry. :]

Bwhahahahaha....

 

[Benw455]

Good info! Thanks

 

[Costner]

Had a similar issue with my 46" Samsung. Clicky, clicky when turning on or off and the relays would continue for 1-2 minutes after startup and after shutdown. A few months of that and all of the sudden there was a loud "bang" and the set went dead.

I turned out to be a leg of a transistor that blew, but it was under warranty so the tech replaced the entire power supply board. It was a revamped version that included upgraded components and looked far superior to the original. That was about a year ago and so far there have been zero problems.

In my case, Samsung offered very good service. They even extended my warranty an additional six months due to the repair.

I think the original reason your caps were bulging is they were full of "stuff" from a little too much Glenn Beck.

 

[Tech Guy]

My brother purchased a 60" Sony LCD. Three months in and it dies with a puff of smoke. Tech came out under warranty and replaced all three power supply boards with heavily upgraded ones and replaced all the large capacitors. Four years later and not a problem.

 

[Leeboy20]

Exact tv and the exact problem my buddy had..... He fixed it for a couple of bucks...... We read on the internet it was a common problem....

 

[bmwpower]

I wonder if you would have been able to fix a tube tv this easily...probably not.

For the guys that do a lot of circuit board stuff...how do you safely solder those leads to make them look like the factory finished product (ie not boogered)?

 

[c5golfguy]

bmw... that's what I was thinking about with the question about ESD. If it was a tube tv, no way in hell would I have even thought about tackling it.

I think to make the solder job look oem, its all in the type of tip that is being used. The tip on the Radio Shack iron I got was pretty big. If it was a little smaller, and I used a little smaller diameter wire, could have been easier. This was my first time trying this, but next time I'll get different tools to get a cleaner look on installation.

Still no issues with the tv today!

 

[ImportTuner]

Good job; thanks for the post

 

[MadMark]

Did you have to discharge the capacitors before you start.
Also, I would like to know the best way to solder a bord like that without the heat damaging the other components.
Great job

 

[c5golfguy]

Did you have to discharge the capacitors before you start.
Also, I would like to know the best way to solder a bord like that without the heat damaging the other components.
Great job

Thanks.

From the research I read, they suggested just unplugging the tv while it was on and it would discharge the caps. I didn't do anything towards discharging them.

They aren't like car audio caps where you have to discharge those things.

 

[Toolhorder]

http://en.wikipedia.org/wiki/Capacitor_plague

That's a laughable article. I have a side vending business in soda/snack/arcade machines and caps in power supplies and monitors have been going bad since the 80's. This isn't a new problem or anything. I have a monitor chassis from about 95 or 96 that has a bad cap right now and I need to fix it. Sometimes just replacing caps doesn't fix the problems though. Here's a picture of mine,



The cap has exploded out the bottom. I'm going to try and replace it first and see what happens.
If you want a clean solder joint you need a good soldering station with adjustable temp. The radio shack stuff won't cut it if you solder much. I use an adjustable model from Hakko, I believe a 900 series with built in ESD protection. I never use an ESD wristband or anything and I've never had a problem.

Someone asked about discharging caps. On a cap that small it doesn't have the ability to hold a charge long. Usually those are filter caps. that smooth out the voltage spikes they don't typically hold a voltage with the power off.
Caps that you have to worry about are bigger in size. You can tell. I picked up a monitor chassis a couple years ago and got a nice zap when my finger connected the two contacts across a big cap in the board. About the size of a D cell battery. Not fun.

 

[nate379]

Just an FYI, your pictures don't load anymore.

 

[ddawg16]

I would be willing to bet the OP was using a Weller iron....I believe the typical tip for something like this would be about a 25W iron...

The typical steps are...

Attach anti static strap to wrist
Remove board
User iron and solder sucker to remove solder
Install new caps making sure to get polarity right
Solder joints....it doesn't take much heat....just a little dab of solder on the tip of the iron....touch to pad and cap leg....then feed solder into joint....you don't want a glob....it should just flow...remove iron...let cool
Clip off excess cap leg.
Do next joint.
Clean with alcohol.
Re-install

 

[Stuey]

That's a great tutorial! *crosses fingers* I hope I don't have to do anything like that on my TV!

 

[c5golfguy]

That's a laughable article. I have a side vending business in soda/snack/arcade machines and caps in power supplies and monitors have been going bad since the 80's. This isn't a new problem or anything. I have a monitor chassis from about 95 or 96 that has a bad cap right now and I need to fix it. Sometimes just replacing caps doesn't fix the problems though. Here's a picture of mine,



The cap has exploded out the bottom. I'm going to try and replace it first and see what happens.
If you want a clean solder joint you need a good soldering station with adjustable temp. The radio shack stuff won't cut it if you solder much. I use an adjustable model from Hakko, I believe a 900 series with built in ESD protection. I never use an ESD wristband or anything and I've never had a problem.

Someone asked about discharging caps. On a cap that small it doesn't have the ability to hold a charge long. Usually those are filter caps. that smooth out the voltage spikes they don't typically hold a voltage with the power off.
Caps that you have to worry about are bigger in size. You can tell. I picked up a monitor chassis a couple years ago and got a nice zap when my finger connected the two contacts across a big cap in the board. About the size of a D cell battery. Not fun.

Thanks man for the info. The radio shack thing I got was adjustable 20/40watt. I saw different size tips on the rack. I don't do this very often, so I thought the iron was ok. I knew my Snap-On butane soldering iron I used for car audio stuff for the last 15+ years would be too hot.