Q. I have been in my course for 3 years and I have a question about troubleshooting. Are you supposed to use Kirchhoff's laws to make voltage checks first, or do you use ohmmeter checks first.
A. It depends. Generally, you first try to get as much information as you can about how the pice of equipment is malfunctioning. If you can power it up, you first look for obvious signs of components overheating.
Then you start with the voltage checks. But in many cases it is not possible to power teh equipment up. In these cases you start with ohmmeter checks. This often happens with faults in the power supply. A filter capacitor will short and/or a rectifier will short or open.
This makes it impossible to power the equipment up. Anoth example is when there is an open in the AC line cord. This is best checked by unplugging the cord and doing ohmmeter checks on it.