How to solder capacitors?

Soldering capacitors is not difficult. First you will need access to the rear of the printed circuit board which has all the solder connections. I don't know which type of caps you are talking about but you must be sure to make a note of which way round the existing capacitors are seated on the board. Large value caps usually have two solder tags at one end or wires coming out of each end. If there are two solder tags at one end then the plastic sleeve on the can will usually have a series of dashes down one side - this indicates that the negative connection tag is on that side. Alternatively you may have a series of plus signs to indicate the positive connection. Caps with a wire at each end of the can will also be marked with plus and minus signs to show which way round to connect. You will need to make sure you replace the caps the correct way round.

For a soldering iron about 25 watts is usually fine for this type of work.

Suggest you also use 'solder wick' to remove the existing solder when you take out the duff caps. This is used by placing the solder wick over the joint and applying the soldering iron to the solder wick. After a short interval the solder melts underneath the wick. It is drawn into the wick and leaves a clean board. You may have to clip off any solder laden wick if there is much solder to remove.

With all the solder removed you should be able to lift off the old caps and replace with the new ones. For good joints make sure that there is no corrosion on the tags or wires. Failure to do this will result in what is known as a dry joint. It looks like a good soldered joint but will not conduct electricity.

When soldering in the new caps make sure you use resin cored electronic component solder. Other types have a high melting point and will result in bad joints. Apply the solder between the iron and the connection you wish to make. As soon as it flows and makes the joint remove the iron. You may have to apply solder on both sides if it is a tag connection.

Try not to heat up any semiconductor devices with hot solder. The usually require lower wattage irons to prevent overheating.

Just a hope - when replacing caps with a wire at each end you can sometimes clip off the old wires close to the can and use the wire left in the board to connect the new component.

Happy soldering.

What makes you think that the capacitors are bad? Everyone thinks that capacitors are the route of all evils, but that's like saying that all people are bad. The capacitor issue was a short term issue from over a decade ago. If these are electrolytic capacitors, most of the bad ones pierce the very top, and leak electrolytic fluid. If you see this, they are certainly bad. If not, you should take one lead out of the circuiit, and measure them.