1, in order to further confirm the chip problem, first of all in withstand voltage current power is pretty stepper motor power drive pipe, restore the chip power pin, using leds to replace stepping motor's winding circuit simulated load. After electrify, leds are bright, namely each winding are electricity, it is not in conformity with the requirements of the line input step pulse response, thus confirm the chip has been damaged. 2. Solution: the chip is not on the market, in the case of drive casing space allows, using the combination circuit which USES existing D flip-flop at hand and the combination of the nand gate design an annular pulse generator, production on a small PCB, dismantling the original chips will small PCB by pin is installed on the original chip bonding pad. Still using light-emitting diodes as simulation load, after electrify plus one step pulse according to the phase sequence in turn to shine. Demolition of simulation load, access to the host, electricity, equipment running normally. 3, electric inspection, found a chip abnormal fever. After power will cut off the power supply pin of this chip and static checking, power supply to the ground resistance increases should belong to normal. Measuring the chip power to the ground resistance is small. Check the chip model for a non-standard type, manual, many did not. Confirmed by the line analysis, for the main components of the plate, the annular pulse distributor. 4, this example illustrates, maintenance personnel should not only can analyze phenomena (Flow)To find out the obvious reason (Power tube damage)And at the beginning of every step of the analysis of the fault because of (Pulse generator damage)And be able to use existing components combined alternatives at hand is difficult to solve the problem of the device. 5, failure phenomenon is: once started, drive an external fuse is burning, equipment can not run. Maintenance personnel during the inspection, they found a power tube is damaged, but since there is no data, lost the role of the tube, thought is driven power forward, put on a power tube, after electrify, insurance burned again, change the tube is damaged. By professional maintenance personnel examination, initial analysis is right, namely insurance repeatedly fusing, drive certainly exist an unusually large current, and check out the damage of power tube. But is not clear for the role of the tube. In fact the pipe for step motor drive power, step motor for high voltage starting, thus to withstand high voltage large current. Static inspection, found that pulse annular divider circuit, the power supply to the side resistance is very small, but also not short circuit. According to the number of components in circuit power supply to the side resistance and power consumption analysis should not be so small, so doubt existing components of the circuit to be damaged. the main products: stepper motor, brushless motor, servo motor, stepping motor drive, brake motor, linear motor and other kinds of models of the stepper motor, welcome to inquire. Telephone: