How to remove that capacitor from the board?

capacitor http://vi-server.org/vi/_/cap1.jpg

In the question about damaged power supply I was told to use "a sharp utility knife", but it don't cut that thing (is it epoxy?). Also tried old not-so-sharp scalpel (it can punch that things if pressed hard, but not cut).

knife http://vi-server.org/vi/_/cap2.jpg

What other methods of removing it can you propose?

Update: Mission accomplished:
removed capacitor http://vi-server.org/vi/_/cap3.jpg

  1. The cap is made of aluminum, wrapped in a plastic jacket. The jacket is glued down. Can you slit the plastic and remove the capacitor, leaving the jacket where it is?

  2. Otherwise, try a bit of acetone on the glue and see if it softens any. (Acetone + perfume = nail polish remover.)

  3. If it's a hard brittle substance, try using a hammer and punch to dislodge the capacitor. If that doesn't work, try a bigger hammer!

  4. Last resort:

enter image description here

  • 3
    \$\begingroup\$ I use acetone on everything. Toothpaste? No need! Deodorant? Nay, sir! \$\endgroup\$ – tyblu Feb 19 '11 at 6:27
  • \$\begingroup\$ Used CCl4 and it became softer. \$\endgroup\$ – Vi0 Feb 19 '11 at 11:44

Do you need to keep the cap intact? If not, I would cut the leads, desolder them, and get pliers and gently roll the cap side to side to remove it. I haven't encountered anything yet that has been epoxy-like, so it might come off pretty easily. Of course, you have to use your judgement, so if it doesn't seem to want to release, don't force it.

  • \$\begingroup\$ This is popped capacitor I want to replace. There is other part nearby, so rolling it from side to side is not that easy. \$\endgroup\$ – Vi0 Feb 19 '11 at 2:38
  • \$\begingroup\$ ^This. Just grab it and yank. \$\endgroup\$ – Connor Wolf Feb 19 '11 at 6:56

I'd try to figure out what the substance is - is it softish? That would be either hot-melt or silicone. If it's one of those you can either just cut the leads and pull the thing off (neither one will damage the board in the process), or if it's hot-melt you can heat it up a bit and the thing will come right off.

Given that you can't cut it easily, I'm guessing it's hard as a rock. That means either epoxy, or superglue, and of the two I'd guess epoxy. If it were superglue, you could get some remover (yea, they make a chemical that will soften superglue!), but if it's epoxy you've no such luck (the only chemical that would work is pretty carcinogenic and thus not readily available). At that point I'd cut the leads and break the cap off - either chiseling it off, or using a thin bladed saw to cut the epoxy above the board (breaking the cap into pieces if need be).

Then, once you've got the cap off, use silicone or hot melt to attach the new one.

  • \$\begingroup\$ The knife slowly comes into it, but not far. It is not very hard. The knife needs a bit of strain to remove after attempt. \$\endgroup\$ – Vi0 Feb 19 '11 at 2:37
  • 1
    \$\begingroup\$ @Vi0, I think you need a bigger knife! (My buddy Dundee can hook you up.) \$\endgroup\$ – tyblu Feb 19 '11 at 6:10

If it is epoxy, heat might work. Try going outside (or at least open the window wide), and use an old soldering iron. Remember that you don't want to save the cap, but you want to keep the board in good shape. Cutting the leads before attacking the glue will be a good idea.


I had same issue. I was trying to replace a bad cap and noticed they're all glued down to the circuit board with epoxy. Carefully cut the joint where the epoxy touches the bad piece with a dremel and try "rocking" the bad piece side to side with some pliers.


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