Analysis and maintenance of: according to the analysis of the fault phenomena, the reason there are three: a lighting system with crystal shutter tube circuit interference of sound reinforcement system; the second is a channel signal transmission line shielded wire poor contact; the third is the link of sound reinforcement system in a faulty equipment. When the overhaul, turn off the dimming system, the sound of the sound response to the speaker, the fault is still. Check the signal channel connected to the transmission line, turn off all the audio playback device, the fault is still not eliminated.Vf4service manual download site
Turn off the mixer, then turn on the power amplifier, or there is a sound of communication. Turn off the equalizer, then turn on the power amplifier, and the sound disappears. Check the signal connector of the mixer to the equalizer.. The test line resistance is normal, the line is not faulty, the fault may be in the equalizer. Turn on the bypass switch, the sound disappears immediately, the sound is returned to normal. Then remove the equalizer, the signal input line of the equalizer jump pick in exciter signal input port, or replace a equalizer to cope with spot use.Vf4service manual download site
Turn off the power of the equalizer, open the cover, observe the power supply system in the equalizer rectifier, filter circuit, not found abnormal. Remove the rectifier, filter circuit board, with a meter measuring rectifier diode and filter capacitor, found a 4700 V F/50 electrolytic capacitor leakage. Change the same capacity and breakdown of the capacitor, troubleshooting.Vf4service manual download site
Explanation: in the acoustic system, the low frequency exchange sound, generally from above several reasons. In this case, the large capacity electrolytic capacitor in the circuit plays a role in filtering the grid 50 Hz and other interference ripple, provide the circuit with flat DC voltage. If the filter capacitor appear open circuit or leakage, will lose filtering function and produce the above fault.Vf4service manual download site