After turning on the machine, such as the discovery of no power display, no action, the first thing to look at the power supply seat within the insurance is damaged.

Analysis and judgment: it is possible that the user ground wire and the fire wire or zero wire mixed, and not grounded (the machine ground is connected to the machine shell), there may be a short circuit in the machine, components aging short-circuit phenomenon, resulting in damage to the insurance.

Detection and solution: take out the fuse to see if there is a fracture, use the multimeter through the broken file to measure whether to disconnect, replace the new device

Analysis and judgment: may be due to a long time in the open use state, the temperature will gradually rise leading to alternating melting words can go off or words can go to the ceramic part of the fracture.

Detection and solution: Use a shaking table to measure the insulation strength of the words to go, insulation strength below 200M, has been unable to use, must be replaced by a new transducer. Because the internal ceramic of the transducer will also be due to long-term use of fracture, can not work properly. 

Analysis and judgment: the power tube on the motherboard will be because of the machine for a long time without interruption, or too little cleaning fluid for a long time, the power tube short-circuit situation.

Detection and solution: gear power tube connected to the motherboard, using a multimeter to measure the resistance of the power tube pins on both sides, under normal circumstances should be about 22, after taking down the power tube (disconnected from the motherboard), measuring its various pins should not be connected between. 

Analysis and judgment: damage to the voltage regulator is generally caused by a small resistance or short circuit in the power tube, after the power on, itself rarely damaged.

Detection and solution: According to the characteristics of the diode, positive conduction, reverse as of. Measured with a multimeter diode file, the forward resistance value of about 70, reverse ∞. If the value deviation is too large or forward resistance value is also ∞, replace the new voltage regulator. 

Analysis and judgment: the same regulator condition

Detection and solution: the same according to the diode characteristics (the bridge itself is composed of diodes) 

Analysis and judgment: long continuous work, components aging related, or sometimes infiltrate cleaning fluid related.

Detection and solution: in the machine does not work state, disconnect the control board and the motherboard, the motherboard energized, such as the machine works, it means that the control board is damaged and needs to be replaced. 

Analysis and judgment: Due to the long working hours of the machine, inductors, transformers belong to the heat dissipation components, its own may be too high temperature two melted, burned, resulting in short circuit.

Detection and solution: inductor, transformer damage, in most cases intuitively can see the traces of burned, replace the new device