Many problems that circuit boards have may be repaired by replacing defective parts. You do not have to be an electronics engineer to remove and replace bad parts. Parts that commonly need to be replaced include capacitors, transistors and various electronic chips. If, through visual inspection or through circuit analysis, you can identify which part is defective, you can usually repair a circuit board.
Identify which part you want to replace on your circuit board. On the other side of the circuit board, there are solder points that connect the parts to the circuit. Identify the soldering points of the part you intend to replace
Heat your soldering iron to operational temperature. Place the circuit board, with the solder side up, on a flat and well-lit surface.
Press the tip of your soldering iron against the solder point that is supporting the part you want to remove. Be careful not to touch the soldering iron to any other parts. The existing solder should soften and turn to liquid. If the solder does not melt, your soldering iron has not reached operational temperature or is not rated at a high enough wattage to melt that specific type of solder. Continue to hold the soldering iron tip in the melted solder.
Suck up the liquid solder using a de-soldering device. There are several types of de-soldering devices, but they all generally work with suction. Repeat this step until all of the solder has been removed from all terminals of the device you intend to replace. De-soldering braid may also be used by placing the braid into the melted solder and allowing it to bond to the braid before pulling it away.
Replace the part that has been disconnected from the circuit board. The old part should come out of the board easily. If it does not, make sure that all of the solder has been removed. Solder the new part into position, ensuring that each terminal is making contact with the correct port in the circuit.
When melting your solder, make sure that it does not bleed into other solder points on the circuit board.
Use caution when working with hot soldering irons.