Stay inside the machine, due to the failure after video could not be removed with the out of the box key, so the first power HouGaiBan, video of the operation to take out the machine by hand. zQQservice manual download site
 zQQservice manual download site
According to the phenomenon analysis, the fault is not in the system control circuit, is in the power supply circuit. First check the power supply circuit, measuring output power connector "001" the feet of ground resistance is no exception, electricity measure voltage are normal, the connector each feet of power supply circuit works well, judging on the basis of fault in the system control circuit. zQQservice manual download site
 zQQservice manual download site
The machine control circuit by microprocessor control system IC2001, timing, microprocessor IC7501, functional extents IC6801 and peripheral components. System control circuit is working, the three pieces of integrated circuit to control the VCR each function harmoniously, and mutual information, the transmission of the information contained in the following two aspects: (1) is the content of the serial CLOCK signal (CLOCK), Ann is a sync signal, the microprocessor job can guarantee the accuracy of the data transmission and recognition; (2) is a serial DATA (DATA) signal, work with microprocessor control. zQQservice manual download site
 zQQservice manual download site
IC200144 feet were added to the output of the serial clock signal and IC63012 IC750117 the feet, IC750118 feet for the serial data output. If these three pieces of information transfer between integrated circuit line out of the question, the video will not work properly. IC20011 maintenance, test and 8 feet and IC75011 voltage of + 5 v (normal); IC200145 foot measurement of resistance for 4 k Ω, is normal; Measuring the 14 feet over the ground resistance of only 0.2 k Ω, significantly lower than the normal value of 4.2 k Ω, explain the formation of the serial clock signal or fault in the relay circuit. According to the analysis, the causes of abnormal IC200114 feet over the ground resistance are: (1) IC2001 14 feet internal circuit damage; (2) 17 feet IC7501 internal circuit damage; (3) IC6801 2 feet of internal damage; (4) the capacitance C6011 serious leakage. In order to determine the fault parts, through the release in this three corresponding pins, IC testing of resistance to judge respectively. Try putting IC2001 14 feet, detects the feet of ground resistance is 5.6 k Ω normal, show that the circuit inside the foot is normal; Then cut IC6801 attachment 2 foot, detects the feet of resistance is 5.6 k Ω, also normal, C68012 foot internal circuit is normal; And then cut through IC7501 17 feet, the foot of resistance detecting, 0.2 k Ω abnormalities, shows that integrated circuit inside the block IC7501 17 feet has been damaged.

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