1. No display on startup.
Causes and measures: Check whether the fuse, power supply circuit, display is damaged, and whether the battery voltage is too low.
2. Abnormal DC voltage
Causes and measures: The A/D converter +IN and -IN can be short-circuited, and the display is zero, which means that the fault is in the DC voltage input part before the A/D converter. If the DC voltage is normal, the AC current or AC voltage is abnormal, usually the I/V converter or AC/DC converter is damaged.
3. The ohm gear is abnormal
Causes and measures: It may be caused by the open circuit of the thermistor.
4. The capacitor file is abnormal
Causes and measures: The main reason is that the ICM7556 integrated block is damaged.
5. During measurement, the deviation of the ohm gear indication value is too large
Causes and measures: Generally, the transfer switch is in poor contact, just wipe it with anhydrous alcohol.
6. The deviation of the AC voltage gear is too large
Cause and action: Adjust the calibration potentiometer in the AC/DC conversion circuit. If the deviation of each gear is too large, the reference voltage value should be adjusted (normal value 100mV).
