1. Intuitive method:
Use hands, eyes, ears and nose to intuitively find the faulty part. Such as: broken wire, dummy welding, component contact, poor contact of the plug-in, overheating of components, ignition and smoke, burning, oil-deficient wear of mechanical transmission parts, excessive gap or rolling, abnormal noise, etc.
2. Circuit parameter measurement method:
Use a multimeter to measure the voltage and current resistance values of each point of the circuit, and compare it with the normal value to determine the fault location. If necessary, you can compare it with the new machine to determine the fault.
3. Replacement method:
For suspected components, plug-ins, and normal similar parts, the purpose is to narrow the scope of fault search, and faulty components can be found in replacement.
4. Cut-off method:
Cut off the suspected circuit from the whole machine or unit circuit and gradually narrow the fault search range. If the working current is too large or there is a short circuit fault, some circuits can be disconnected from the whole machine and check the current changes to determine whether the circuit is normal. .
5. Short circuit method:
For interference, self-excitation and other faults, two points in the circuit can be temporarily short-circuited. The fault disappears after a short circuit, which means that the fault is before the short circuit point, and vice versa, it is searched after the short circuit point. If the DC potential is different between the two points to be shorted, it should be shorted through a capacitor of appropriate capacity.
6. Test instrument inspection method
Use special testing instruments to test the entire instrument machine or components, which can often effectively detect obstacles and improve repair quality.