Digital multimeters, the multi-purpose electronic measuring instrument, voltage meter, ammeter, including general ohmmeter and other functions.
For a fault multimeter, first of all, should check and identify the phenomenon of failure is common, or personality, and then distinguish the situation, symptomatic solution.
1, if all the files can not work, should focus on checking the power circuit and A/D converter circuit.
2, if there is a problem with individual files, the A/D converter and the power supply are all working properly. If the small signal is not accurate or the number of the display is large, the contact of the measuring switch should be checked carefully.
3, if the measurement data is unstable and the value is always increasing, the input of the shorted A/D converter is not zero, the performance of the 0.1 F reference capacitor is usually bad.