1. Tapping Method

Gently tap the circuit board or components with a small rubber mallet or other tapping tool to see if it triggers errors or shutdowns.

2. Visual Inspection Method

Use sight, smell, and touch. Sometimes damaged components may discolor, bubble, or show burn marks; burnt-out devices emit a distinct odor; short-circuited chips may feel hot; poor solder joints or detached components can often be spotted with the naked eye.

3. Elimination Method

This technique involves removing certain plug-in boards or components from the instrument to pinpoint the fault source. If the instrument functions normally after removing a specific board or component, that is where the fault lies.

4. Replacement Method

Requires two instruments of the same model or sufficient spare parts. Replace a faulty component in the malfunctioning unit with a known-good spare part to determine if the fault persists.

5. Comparison Method

Requires two instruments of the same model, one of which is functioning normally. This method also necessitates essential equipment such as multimeters and oscilloscopes. Comparisons can be categorized by nature: voltage comparison, waveform comparison, static impedance comparison, output result comparison, current comparison, etc.