Samsung ln40a550p3f power cycling? Here’s how to fix it!

The Problem: Bad Capacitor

For a week or two prior to my Samsung ln40a550p3f dying, I noticed it was taking a long time to power on. Like, 30 seconds or more. The problem got worse a few days later when it would turn on, quickly turn off, then turn back on. A day or two of that and it would power cycle for 10 minutes before finally coming on. In the end, it would just power cycle for hours and would never turn on.

Some quick googling lead me to many different places, in fact, a whole underworld of people paying “electronic experts” (as seen on http://www.fixya.com/) for advice on how to fix their TVs, only to find the expert advice was “Oh, you need to contact a qualified Samsung TV repair person” or “check the power supply, it’s probably bad”.

So the real problem in my case is capacitors (wiki) that have gone bad. You can tell when a capacitor is bad because it’s bulged out at the top. You probably do not need a whole new power supply, a couple capacitors should do the trick, and they are dirt cheap!

Skills & Supplies Needed

I should get this out in the open, I can count on one hand the number of times I have soldered in my entire life. So I’m not an advanced geek in that department. However, I felt pretty confident because this is a pretty small job; two capacitors. If you’re not the kind of person that jumps right in, I’d suggest going through a few tutorials on How To Solder on instructables.com. Here’s what you’ll be needing.

1. Soldering iron
2. Soldering wire
3. Capacitors – My TV came with 10v 1000µF, I replaced with 25v 1000µF. I’ve read that a higher voltage capacitor will prevent this problem from happening again.

You can find soldering supplies anywhere. Check your local electrical store or Radio Shack, I’m confident you’ll be able to find all of the supplies/tools listed there.

The Solution: TV Surgery

Taking the tv apart is dead simple. Just remove all of the screws and pop off the back. One word of caution: Unplug your TV and let it sit for a good 20 minutes or so to allow the capacitors to discharge.

The part we will be focusing in on is the board in the center of the tv. Here’s the back board:

I took a couple close up shots and circled the bloated capacitors.

Here’s a couple close ups of the new and old capacitors:

So the only thing left is to remove the old capacitors and solder the new ones.

• Mark the back of the board where your two capacitors are located.
  

• Apply the soldering tool to those areas until the solder gets soft/liquid. At that time you should be able to work the dead capacitors free.
• Feed the wires on the new capacitor through the holes on the board. NOTE: There is a positive and a negative side! You should be able to see on the board where it is labeled with a “+”. Likewise on your capacitor you’ll see some marking indicating which size is negative and which side is positive.
• Once the new capacitor is in place, bend the wires to the side so the capacitor will stay in place without you actively holding it.
• Do the soldering. This is where you’ll want to look for soldering tutorials. I’m no expert. I simply applied the tip of the soldering tool to the area, fed in enough wire to where it created a liquid ball that fell into place. One trick I can give is to pull the wire away first, and then your soldering tool tip. This avoids soldering the spool of wire to the board, which I did initially.
• Trim excess wire from the capacitor.
• Reassemble TV.

That’s about it! It’s a drop dead simple fix, should only take about 15 minutes and will save you a good $150-200. Not bad right? Here’s the finished capacitors:

Here’s the finished TV, powered right on!

I hope this was able to help at least one person out there! I know from now on I’ll think twice before taking my TV in for repair.