This machine boot into the DV tape, normal load, however after a few seconds the machine power indicator light flicker alarm, LCD display FO5 fault code and then shutdown protection, after re boot failure remains the same, but normal storage and unloading. Analysis and maintenance: the circuit is shown in figure. The machine has self check function, when the fault occurs, can protect themselves, and the corresponding fault code. According to the fault code FO5, the preliminary judgment of the fault in the drum and drum servo drive circuit. Open the machine cover, and power to boot into DV tape, the machine can normal loading and unloading, illustrate the mechanical part of everything is normal, but the drum does not turn. After replacing the drum set, the fault is still, that is not drum itself causes, so focus on examination of drum servo driving circuit. The IC2201 (21) ~ (23) ~ (14) foot voltage is 2.1V, and the (15) - (17) - (13) foot is normal. Disconnect (13), (14) pin, pin voltage are 0.2V and 2.8V, indicating that IC2201 is not damaged. And only the driver block IC2202 is not normal, can cause the IC2201 pin voltage is not normal. With digital million with meter is used to measure IC2202 the pin voltage and normal voltage contrast, discovered that in addition to (2), (4) and (6) and (9) and (11) and (13) foot and normal values are in good agreement, the other of the pin voltage were significantly lower, touch IC2202 feel significant fever. According to the circuit analysis, can cause the IC2202 is not normal external factors have been excluded, only the IC2202 itself is damaged, can cause the voltage is not normal. This new integrated block, recording and playback can be normal.