1. Waveform analysis.
Observe the voltage waveform, amplitude, period (frequency) of each key point of the circuit with an electronic oscilloscope. For example, if the clock oscillator starts to vibrate or not, the oscillation frequency is 40kHz. If the oscillator has no output, it means that the internal inverter of TSC7106 is damaged, or the external components may be open. Observe that the waveform of the {21st} pin of TSC7106 should be a 50Hz square wave, otherwise, it may be the damage of the internal 200 frequency divider.

2. Measure the component parameters.

3. Hidden troubleshooting.

4. Appearance inspection.
You can touch whether the temperature rise of batteries, resistors, transistors and integrated blocks is too high by hand. If the newly installed battery is hot, the circuit may be short-circuited. In addition, you should also observe whether the circuit is broken, soldered, mechanically damaged, etc.

5, detect the working voltage at all levels.