A typical printed circuit board or PCB has a large number of active and passive electronic components that are connected together through thin copper traces. The active components are the ones that use power to operate, such as electronic chips. The passive components, on the other hand, do not require external power. Common examples of passive components are resistors and capacitors. If a capacitor on a PCB goes bad, it can be replaced using some specialized tools.
Instructions
Surface Mount (SMD) Capacitor Desoldering
1 Turn the soldering iron on and set it to a temperature of 370 degrees Celsius.
2 Place the PCB on a flat and dry surface with the component side facing UP. Identify the capacitor to be desoldered.
3 Hold the capacitor by the middle with tweezers and gently touch one of its soldered ends with the tip of the soldering iron. Keep the tip there for two to three seconds, and then quickly move it to the other side of the capacitor and keep it there for two to three seconds. Continue this process until the capacitor comes loose, at which point pull it out using the tweezers.
4 Place the copper braid on top of one of the pads from where you have removed the capacitor and gently press it with the tip of the soldering iron. Keep the tip there till all the solder flux has been absorbed by the copper braid. Repeat this step for the other pad.
5 Clean the pads with an alcohol swab.
Regular Capacitor Desoldering
6 Turn the soldering iron on and set it to a temperature of 370 degrees Celsius.
7 Place the PCB on a flat and dry surface with the component side facing DOWN and identify the pins of the capacitor that needs to be removed.
8 Place the copper braid at the junction of one of the capacitor pins and its corresponding pad and gently press it with the tip of the soldering iron. Keep the tip there until all the solder flux has been absorbed by the copper braid. Repeat this process for the second capacitor pin.
9 Turn the PCB over with the component side UP and gently lift the capacitor with the help of tweezers. Do not use excessive force. If the capacitor does not come out easily, briefly touch its pins with the soldering iron while pulling it out using the tweezers. This will loosen the solder bonds and the capacitor will come out.
10 Clean the pads on both sides of the board with an alcohol swab.
