Wednesday, 22 July 2015

Know A Bad Circuit Board

Know when a circuit board is bad.

A printed circuit board is a plastic board that contains a number of traces made out of copper or another conductor which are used to connect individual electronic components into complicated electronic circuits. A circuit board is generally a very reliable device, but after physical damage or exposure to electrical conditions it was not built for, a board can become damaged to the point of failure. Determining when a circuit board has a problem is a useful skill, though checking one to see if it is bad can seem like a daunting task to someone who is unfamiliar with electronic devices. There are a number of techniques to check for a bad circuit board.


1. Inspect the circuit board for signs of visible physical damage. Watch for components that appear to be cracked or burned. Turn the board over and ensure that the conducting traces on the bottom of the board don't appear scratched or cracked. Check all silver solder blobs to ensure that none have been damaged or come off of the board.

2. Turn off the power supply to the circuit board. Use a multimeter set to the resistance or ohms setting to test the connection between the positive and negative connections from the power supply; if there is continuity between these two points the power supply may be shorted out.

3. Turn on the power supply. Use a multimeter set to the voltage setting to check the voltage across the power supply. Ensure that the meter reads the correct voltage for what the power supply is rated at; the voltage rating can be found in the manual for the circuit board or may be printed on the power supply itself.

4. Remove any chips or socketed components from the circuit board. Check their connections to ensure that they are not corroded or dirty. Clean them with a pencil eraser if they appear dirty. Seat the chips back into their sockets after thoroughly cleaning them.

5. Check the manual or schematic for the circuit; there may be other points with test voltages that you can measure with the multimeter. Testing points other than the power supply will vary from board to board, so ensure that you follow the troubleshooting steps in your user manual or schematic carefully.

Tags: circuit board, power supply, ensure that, board printed, circuit board printed