JD
Well-Known Member
Just thought I would pass this along. Applies to the 1100, 1200, 1400, 1700 older QSC amps that may randomly mute for a few second to a minute.
Had a 1200 that was driving me nuts as it took about a half hour to start doing it. Turns out that QSC uses an LED soldered in the middle of the pcb (not an indicator) to produce a voltage reference. After enough years, they get flaky and go open circuit at just the right temperature! Had two other amps about the same age, and sure enough with a heat gun and cold spray they were flaky too! 10 cent part, run of the mill LED. Labeled LD3
Had a 1200 that was driving me nuts as it took about a half hour to start doing it. Turns out that QSC uses an LED soldered in the middle of the pcb (not an indicator) to produce a voltage reference. After enough years, they get flaky and go open circuit at just the right temperature! Had two other amps about the same age, and sure enough with a heat gun and cold spray they were flaky too! 10 cent part, run of the mill LED. Labeled LD3