Replacing 2 bad capacitors on plasma TV

http://intrepiderie.com/intrepiderie_blog/replacing_capacitors

Warning: This is just a blog entry. I am not a professional. There is no editor or fact-checker, so it is quite possible that there are inaccuracies. If you make a mistake, damage or injury could occur. If you don't have experience with this kind of stuff, don't do it. This blog is for entertainment purposes only. These are not official instructions.

Symptom: The plasma TV overheats and turns off by itself. It stays off for a minute before coming back on. As caps get worse, the TV overheats and automatically turns off more frequently, and stays off longer. Eventually, the TV will no longer turn on.

Fix: Replace 2 bad caps. Note that you will need a soldering iron with a fine needle-nose tip, since the components are assembled by precise chip-soldering robots, and everything is very close together with thin traces on the PCB boards. It is hard to work on these units by hand.

Steps:

  1. Place a clean blanket on the floor, or coffee table, or couch.
  2. Remove power and AV connections from the plasma TV.
  3. Take the TV down from the wall and place it face down on the blanket.
  4. Remove screws and take off the back panel.
  5. Follow electrical discharge procedures, because caps can hold power even after the TV is unplugged, and you can get a nasty shock if you are not careful.
  6. Locate bad caps by looking for obvious leaking, or it may be just subtle bulging of the caps, on the top or sides.
  7. Determine which PCB board the bad caps are on.
  8. Use permanent marker to note the direction that the PCB board goes in relation to the TV, and the direction of the caps.
  9. Use permanent marker to note which ribbon cables and other connections go to that board.
  10. Remove the various cable connections.
  11. Unscrew the PCB board and place it on the soldering workbench.
  12. Use desoldering tape (or solder sucker) and soldering iron to remove solder from the bad caps. Pull the bad caps.
  13. Use super fine drill bit to clean out solder joints if the desoldering tape does not get it all, but be careful not to wreck the traces that are on the board.
  14. Use notations written on the bad caps to determine which replacements to order. Get the new replacement caps.
  15. Insert replacement caps into solder joints and solder into place from the back side.
  16. Trim excess wire on opposite side of PCB board.
  17. Put everything back together by following the notes you made previously with permanent marker.

 Conclusion: I did this a couple years ago and the plasma TV is still going strong. It did automatically shut off once the other day, so I may eventually have to replace the caps once again if it starts doing that more frequently.

 

7-Feb-2017 Update: The replaced caps are still working fine on the Plasma TV. We had a different LCD display that was shutting off recently, and I was hoping that I could make the same type of fix, but when I opened it up, all the caps looked fine, none were bulging or anything like that, so I could not fix it. I guess sometimes it is hard to know what caps (if any) have gone bad - on the successful fix of the Plasma TV, the caps were just slightly bulged up on top, not leaking, nothing too bad. But obviously that was the sign to look for, because replacing them fixed the issue.

 

 

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