Digital multimeter troubleshooting can be done roughly as follows.
1. Appearance check.
You can touch the battery, resistor, transistor, integrated block temperature rise is too high. If the newly loaded battery is hot, it means that the circuit may be short-circuited. In addition, it should also observe whether the circuit is broken, desoldering, mechanical damage and so on.
2, waveform analysis.
With an electronic oscilloscope to observe the circuit voltage waveform, amplitude, period (frequency) and so on.
For example, such as measuring whether the clock oscillator vibration, if the oscillator has no output, indicating that the internal inverter is damaged, it may also be an external component open circuit.
3, measuring component parameters.
Components within the scope of the fault, online measurement or offline measurement, parameter values should be analysed. For resistance online measurement, should consider the impact of the components connected in parallel with it.
4, hidden fault elimination.
Hidden fault refers to the fault is hidden, the instrument is sometimes good and sometimes bad fault. Such failures are more complex, common causes include solder joints, loose, loose connectors, poor contact with the transfer switch, component performance is unstable, the lead will be broken and so on. In addition, also includes some external factors caused by. Such as high ambient temperature, excessive humidity or intermittent strong interference signals nearby and so on.
5, detect the working voltage at all levels.
Detect the working voltage at all points, and compare with the normal value, first of all, the accuracy of the reference voltage should be guaranteed, * It is good to use a piece of the same model or similar digital multimeter for measurement and comparison.
Excluding the above possible reasons, the digital multimeter damage may also be due to the error of the measuring gear
Caused by, such as in the measurement of the AC mains, the measurement gear selection placed in the resistance block, this case table
Once the pen touches the mains, the internal components of the multimeter can be damaged instantly.
Therefore, before using the multimeter to measure, be sure to check whether the measuring position is correct.
At the end of use, place the measurement selection at 750V AC or 1000V DC.
In this way, no matter what parameters are measured by mistake in the next measurement, it will not cause damage to the digital multimeter.
