ZED14 faulty - help needed

Other A&H Products
1

I have a rarely used ZED14 and in the last concert it was playing up.

There is an echo and crackle that comes from channel one when the fader is moved. The sound is heard regardless of whether the channel is mute or not. It also happens regardless whether there is a signal entering the channel or not. It also can not detect any signal coming from the jack insert. I have not tried the XLR mic input.
Also if I do not touch channel1 fader but leave it at about 0db, and then move the master fader up and down, it makes the same crackle and echo but at a much lower volume. It sounds more like scratching vinyl.
And on the channel1 control, the PK! lights up bright at about -5db.

My sound engineer said that during the event there were a few other channels making the same noise but right now in my workshop it seems to be only channel1.

Shall I open up the mixer and look at the fader? Perhaps clean it.

2

Try getting some contact cleaner and spraying it into the fader track and then exercise the fader by moving it fully to the top, the fully to the bottom several times. That will work the cleaner into the fader.

3

Yes. Tried that with the fader on channel 1 and also master fader but it has not made any difference.

4

I have swapped out the fader on channel1 for a new one. However, the fault persists. I think now that the fault is in the toggle for the audio pan on channel1. Is it possible to replace the toggle pan (removing it from the channel circuit board and soldering a new one in its place) or do I have to order an entire new channel1 circuit board?

5

It sounds like there is DC voltage passing through the fader.
Disconnect the ribbon cable from Ch.1 and see if the rest of the mixer
works OK then.