Inspection work before repairing the analog multimeter

The failure rate of the pointer type meter head is damaged, the internal components are burned, deteriorated or moldy, and the following inspections should be done before repair:

(1) First put a new battery into the meter, set the multimeter to the r×1, r×10, r×100 or r×1kω gear, short-circuit the two test leads, and see if there is any indication on the hands of the meter. If there is no indication, it is usually because the fuse (usually 0.5a, such as mf47 meter) or the meter coil is open circuit.

(2) Use a soldering iron to solder one end of the meter head, use another good multimeter r×1kω to measure its resistance, and observe whether the meter head is deflected. If the internal resistance of the meter coil is 0ω or ∞, and the pointer of the meter under test does not deflect, then the meter coil is short-circuited or open-circuited; if the meter needle is unstable, it means a partial short circuit or poor contact; if the resistance value is normal but the pointer does not deflect, then It may be stuck by foreign objects.