Fixing the Samsung LCD TV power-cycle problem.

If you bought a Samsung LCD TV in the 2007-2009 era, you may be experiencing a very frustrating problem with your TV.  Power cycling.  If you have a TV that is experiencing this problem, when you try to turn on your TV, you will hear your TV click on and off (and make the power-on notification chime if enabled) in repetition. Depending on the stage of your problem, your TV may or may not eventually turn on and stay on of you wait long enough (ours was taking several minutes before it would stay on), otherwise it will just stay in this cycle of powering on and powering off.  Very frustrating!

Now before I get started let me be clear, I like Samsung products.  They have some duds (Bell's version of the Samsung Galaxy S phone is horrid) which makes me wonder what they are doing at times, but for the most part their products, especially their TVs, are top notch.  As long as you do your research, despite a few screens that have this problem, I would still recommend Samsung TVs.

What causes this problem?  Simple.  Samsung wanted to save money on components, and cheaped out on some of the internal parts.  In this case, instead of putting in properly spec'd capacitors, they put in under-powered (less expensive) capacitors.  Eventually, these capacitors will blow, which usually happens right after the warranty expires.

If you were to get a repair man in to fix the problem, it would likely cost a couple hundred dollars.  Replace the TV?  At least $1000.

The good news however, is that with a little electronics know-how, and a little change from your pocket, this problem can be easily fixed.  The purpose of this article is to explain to anyone who may be unlucky enough to be experiencing this problem, how they can fix the problem themselves.  Please keep in mind that I did this fix on a Samsung 46" LCD, model number LNT4661FX.  Depending on the model, the components required may be slightly different.  In other words, I will not be liable if something goes wrong. :-)



Parts needed -

Before beginning, you will need to buy three new capacitors to replace the cheap ones in the TV.  All three of them are 1000uF at 10V.  You will want to replace these with three new ones with the rating 1000uF at 16V.  Any good electronics store will have these, I simply picked mine up at MRO Electronic Supply for 85 cents a piece.  Total cost including tax: $2.68.


Also, make sure you have a good soldering iron (at least 30-45 Watt), solder wick to clean off the old solder, and plenty of fresh solder to put the new components back on.  If not, pick these up at your local electronics shop as well.  $20 should get you everything you need.

Now, we're ready to proceed.



Doing the Repair -

First, find a clean, flat, staticless surface to lay your TV on, and lay it screen down.  Make sure there is nothing that might scratch or damage the screen.  Then proceed to remove all the the screws to remove the back panel of the TV.  On my model, there were 18 screws.  Then very gently remove the back of the TV to expose the electronics.  This is how it looks:

Back panel removed.

I'm always shocked when I see this much empty space.  I always expect to see a cluster of endless electronics jammed into the case, but I guess this comes from working with small electronics that are always getting smaller and smaller, yet we still want big screen TVs.

Notice the metal shield just to the right of center on this picture.  The electronics we want to get to are under this shield, so we need to remove it.  There are 7 screws holding this shield in place, remove them and the shield will pull off.

Board shield removed.

The next step is to carefully unplug all the ribbon connectors that are running onto the board.  There are 6 connectors, each will simply pull out.  Do this carefully to avoid damaging the connections.  You can see the ribbons running into the board in the images below.

Board with ribbons still connected.

TV compartment with board removed and loose ribbons.

Then the main board will need to be removed.  There are 6 screws around the sides of the board.  Remove them all, and the board will simply lift out.

Again, place the board on a clean flat table that you can use as a good work bench.  You will see the cluster of capacitors on one of the corners (bottom right in the image above).  You will probably see the offending capacitor(s) right away.  In the image below, you will see the blown capacitor that was causing the problem in my TV (it's the one that is oozing out electrolyte).  The capacitor next to it looks like it is about to pop as well.

Blown capacitor with oozing electrolyte.

Using your soldering iron and solder wick, remove the offending capacitors.  While you're in there, you might as well replace all three of the same specs, which is why I suggested buying three capacitors earlier in this article.  Make sure you know which solder connections on the back of the board are the ones that correspond to the capacitors you want to remove.

Back of board showing solder connections.

The following image shows which capacitors I removed.  Each of the circles on the board represent where a capacitor was.

Old 1000uF 10V capacitors removed.

Now it's time to put the new capacitors on.  Simply slide the new capacitors in, noting that the thick black line on the edge of the circle signifies the negative side of the capacitor.  Make sure that the new capacitors are not put on backwards.  Solder the components onto the board, and clip off the excess wire from the back of the board.  The image below shows the new capacitors mounted on the board after soldering.

New 1000uF 16V capacitors soldered on.

Now it's time to reassemble your TV!

-Slide the board back into place on the TV and replace all the screws.
-Reconnect all ribbons to the board.
-Slide the shield back into place and replace all screws.
-Replace the back cover of the TV.

Plug in the TV and test it out.  Make sure everything works.  And we're done!


It's as simple as that.  Very frustrating problem (one that really should have never happened) that can be fixed with no more than the cost of a morning cup of coffee and a little confidence with a soldering iron.

Good luck!