According to the fault analysis this machine motor steady speed circuit, tape detection circuit and control circuit is no problem; According to the analysis of the headset no voice communication failures may be line of headphones broken or lead wire control circuit has a problem. Firstly the drive-by-wire headset received other machines to listen, to receive sound normal, explain drive-by-wire fuses and from the sound output jack to headsets line between control circuit is no problem, the fault in the machine internal audio amplifier circuit or defective in areas such as the head. For rapid accurately locate the fault location, the head first connection ribbon cable unplug from the circuit board, and then put the headphone volume up, again from the patch resistance capacity elements to join the induction signal, at this time there is noise in headphones, again from the head line of line slot end input signal sensor, and also interference noise in the headset, so head may be damaged, on the head, a total of six lines to the circuit boards, wiring from the head to see: is a neutral line, a line is grounded shield shell (the head), the other four lines are respectively in the two groups leads for head. The head remove the check, found that the head of the neutral line and shielding ground wire is short circuit, we'll try the shielding grounding wire welding, then head line into the circuit of commissioning, this time from the headphones songs sound, troubleshooting.ufDservice manual download site