A Printed Circuit Board commonly Called as a PCB, contains a large number of tiny electronic components, which includes resistors, capacitors, transistors, diodes, and fuses. These components are interconnected with each other through thin copper traces. The distance between these copper traces is generally very small, on the order of less than a half millimeter. Such a short distance makes the side-by-side traces prone to shorting, which results in the components getting electrically connected with one another. Due to this there will be an electrical short in a circuit that may degrade its performance, make it nonfunctional or damage its one or more components.
1.Before you actually go about with repair work on a printed circuit board, you must first pinpoint the root of the problem. Diagnosis of an faulty printed circuit board is carried out in the following steps:
- Identifying the problem with the help of a VI instrument. The alternating voltage is used to test the unidentified pin count.
- The next step is to identify the location of the fault on the board. This requires an examination of the board using a microscope to find out the troubled elements.
- Closely have a look at all the copper traces and all component pins for any possible place where shorts could have occurred.Mark all the places on the board that you suspect of having electrical shorts using a marker.
2.Now use isopropyl alcohol to clean the affected part of the PCB. Once the area is clean, dry away the alcohol with compressed air.
3.Now Turn the multimeter on and set it to the continuity test mode. This can generally be done by turning its knob to a point labeled with three or four curly parallel lines. Insert the red multimeter probe in the socket labeled “V” and the black probe in the socket labeled “COM.”
- Place the tip of the black multimeter probe on one of the two conductors that you suspect of having short and place the tip of the red multimeter probe on the second conductor. During this you should hear a continuous beep sound from the multimeter if there is a short between the two conductors. Repeat this process for all the conductors on the PCB where you suspect of having shorts.