- A diode resembles a small tube with metal legs extending from each end for attachment to a PCB. One end of the diode has a painted colored band. The band signifies that the end is positive and the other end is negative. The diode only allows electrical flow from the negative end to the positive end.
- Remove a diode carefully from the PCB by gently heating the soldered ends until the diode slides out. Only use the same diode type, with the same power and resistance values, in the circuit. Solder a new diode into the circuit, paying extra attention to the band's orientation. Verify that the diode's band is in the same position as the old diode was oriented.
- Do not attempt to remove and repair a diode with power applied to the PCB. The PCB can be damaged beyond repair with a powered board.