To test voltage or continuity of electronics components on laptop motherboard you need a Multimeter. Every technician should know how to use a Multimeter.
Voltage test on laptop motherboard
Turn on your Multimeter, the red probe in the VΩHz port and the black probe in the COM port. Set the dial to DC voltage mode (indicated by a V with a straight line, or the symbol ⎓). Most Multimeters are not autoranging, you need to set the correct range for the voltage you expect to measure. For the laptop motherboard measure set the dial at 200V because the AC adapter voltage set between 12V and 24V.
Place the red probe on the positive terminal of electronic component on motherboard, and the black probe on the negative terminal electronic component on motherboard (I place the black probe on the negative side of power jack).
Example of check charge circuit:
Example of check coil voltage:
If we get the correct reading, we can say the electronic component if good.
Continuity test on laptop motherboard
Continuity is one of the foremost helpful checks for electronic component on motherboard. An electronic component is continuous, when electrical current flow freely from one edge to the other. If there is no continuity, it means an open circuit. If there is continuity, it means a close circuit. Continuity check can be used to test switches, fuses, electrical connections, conductors and other components. A good fuse, for example, should have continuity.
Turn on your Multimeter, the red probe in the VΩHz port and the black probe in the COM port. Set the dial to Continuity Test mode (the symbol ).
Make sure there is no current running through the circuit or component you want to check. Place the red probe on one terminal of the electronic component and the black probe on the other terminal of the electronic component on motherboard. If the probes are connected, the check current flows through. The screen displays a value of zero (or near zero), and the Multimeter beeps. There is Continuity!
If the check current isn’t detected, the screen will display 1 or OL (open loop). There’s no continuity.
Example of check fuse Continuity :
Example of check coil Continuity :
Continuity is the presence of a complete path for current flow.