Test and measurement equipment faults, errors, and malfunctions can be tricky to
diagnose because the source of an unexpected measurement may be difficult to discern. If
you can confirm that your error is not a fault of the equipment being tested, you can focus
on your testing equipment. Leads and probes degrade over time, and may need to be
replaced. A faulty power supply may interfere with the waveform on an oscilloscope. Button
presses may fail to register, or displays will show no output. In a worst case scenario, the
printed circuit assembly in your unit may need to be replaced.