The frequency function of the multimeter mainly repairs the commonly used
Repair method Finding faults should be first outside and then inside, the first easy and then difficult, the whole into zero, focus on breakthroughs. The methods can be broadly divided into the following categories:
Feeling method By virtue of the senses directly to the cause of the failure to make a judgement, through the appearance of the inspection, can be found, such as broken wires, de-welding, short-circuiting lap wire, fuse tube broken, burnt components, mechanical damage, copper foil on the printed circuit warping and fracture, etc.; can be touched out of the battery, resistors, transistors, integrated blocks of the temperature rise, you can refer to the circuit diagrams to find out the reasons for the temperature rise abnormalities. In addition, the hand can also check whether the components are loose, integrated circuit foot tube is firmly inserted, the changeover switch is not cassette; can hear and smell the sound, odour.
Measurement of the voltage method Measurement of the key points of the operating voltage is normal, you can quickly find the point of failure. Such as measuring the A/D converter voltage, reference voltage.
Short-circuit method In the previously mentioned methods of checking the A/D converter are generally used in the short-circuit method, this method in the repair of weak and microelectronic instruments used more.
Disconnect method Disconnect the suspicious part from the whole machine or unit circuit, and if the fault disappears, it means that the fault is in the disconnected circuit. This method is mainly suitable for the presence of a short circuit in the circuit.
Component Measurement Method When the fault has been narrowed down to a certain place or a few components, they can be measured online or offline. If necessary, replace the components with good ones, if the fault disappears, it means that the components are bad.6. Interference method Using human body induced voltage as an interference signal, observe the changes in the liquid crystal display, often used to check whether the input circuit and the display part is intact.
