Samsung LCD TV: Power on problem/delay with clicking sound and blinking LED

Symptoms: When trying to turn on the TV after a while, it doesn’t immediately turn and makes a clicking sound a number of times with the red LED/light flashing for a few seconds. Finally, the TV turns on and works normally after that. After the TV has been on for a while, immediate turning off and then on again doesn’t reproduce the problem. There are no other symptoms of this problem (picture quality appears to be fine) and TV appears to be working perfectly once it turns on after the initial delay.
This problem actually worsens with time. The TV takes longer and longer to turn on. one guy reported a turn on delay of up to 30 mins; looks like he really wanted to watch TV :-). If you wait long enough to fix this problem, eventually the TV won’t turn on and permanent damage is possible.

Problem: The problem lies in the power supply SMPS unit of the TV. The low voltage filter capacitors in the power supply are faulty. Samsung managed to install under-rated capacitors here. Instead of putting 16V rating capacitors they erroneously installed capacitors rated for 10V. This exposure to over voltage gradually deteorates the capacitors by heating the dielectric oil that is present in these capacitors. Over time with sufficient heat the oil manages to either swell the top of the capacitors and in some case explode the capacitor. The capacitors losose their capacity without the oil in them and are no longer useful.

Here are the models that are known with this problem:

* Samsung LN40A630M1F (would not power up at all)
* Samsung LE40R88BD
* Samsung LN40A500
* Samsung LA40N81BD
* Samsung LN-T##61F
* Samsung LN-T##65F
* Samsung LN-T##66F
* Samsung LN-T##71F
* Samsung LN-52A550P
* Samsung BN68-01024D

Solution: Luckily these capacitors can be replaced at home without the expensive technician call. They are not specialized parts with only two leads and are easy to replace if you have the right tools. They are also easy to identify as you’ll see in the pictures.

Tools Needed:

  • Philips Screw Driver (To remove several screws on the back of the TV and the screws on the SMPS unit.
  • Soldering Iron (20-30 watts) any hardware store
  • Soldering wire with flux in the core radio shack
  • Desoldering wick or pump (preferred) from radio shack
  • 4 Capacitors 1000uF Voltage rating > 16V

I used 1000uF 35V capacitors from radio shack. These are slightly larger than the original ones but will fit just fine.
Moreover, they can handle upto 35V so they are better in a sense.

Cost: If you alread have the tools need the cost is about $1.5 * 4

Steps:

  1. If you don’t know how to solder or desolder watch the Youtube videos on how to do it first. Its easy.
  2. Unmount your TV from the stand or the wall mount and place it face down on a soft flat surface.
  3. Unscrew all screws holding the back coverof the TV and remove the back cover gently. if it doesn;t come of easily it means you have another screw somewhere holding it. Keep the screws in a safe place.
  4. Locate the SMPS power supply unit.
  5. Remove the top of the PSU by unscrewing the retaining screws.
  6. Locate the faulty capacitors on the component side of the SMPS PCB (printed circuit board). They are easy to spot. They will be bulged up and some may have a tiny hole at the top and traces of brown dried oil residue.
  7. Flip the SMPS board so you see the solder side.
  8. Heat you soldering and check if appropriate temperature is reached by melting a small length of soldering wire.
  9. Clean the soldering iron tip on solder cleaning pad or a car board to get rid of the excess solder on the tip.
  10. You will be removing one capacitor at a time so be patient. This will take some time but is easy to do if you follow the instructions.
  11. Now take the soldering iron in one hand and the desoldering pump or the desoldering wick in another and apply
  12. some heat to one of the capacitors lead. Apply heat till you visually can tell that the solder holding the pin has melted.
  13. Apply the desoldering pump at the pin location and suck the solder out. If you are using the wick then just apply the wick to at the spot to absorb the solder.
  14. Once the solder is removed from one pin, do the second pin.
  15. This should free the capacitor and you should be able to pull it out fairly easily. If the pin is still attached to the PCB just apply some heat to melt the solder holding it while moving the capacitor. Remove other faulty capacitors similarly.
  16. Grab the new capacitor and insert in the holes from the component side making sure that the polarity is correct. Capacitors have a +ve lead and a -ve lead and the +ve lead needs to go to hole marked as positive on the PCB and vice-versa. If you fail to correctly match the polarity, you will destroy the newly installed capacitors, so please match the polarity carefully.
  17. Ones the leads come out on the other side bend them outwards slightly so the capacitors stays on its own. Now apply some head with the soldering iron at the base of the joint and intrduce some soldering wire to make the perfect solder. Don’t fret too much if there is too much solder at the joint as long as the it is not touching any neighboring leads or pins.
  18. Once both leads are soldering, cut the excess part of the lead with a small cutter or a nail clipper. Replace other capacitors in similar fashion.
  19. Put the SMPS power supply unit cover back and screw it on. Screw the back of the TV
  20. Turn on the TV and check for the problem. Your TV should no longer click or blink for more than a couple of seconds which is normal.

Your TV should function normally now. There is no guarantee that  the older capacitors in the TV will work as long as the new ones but you know what to do when you spot a faulty one now.