FADERS MOVING

[Carlo]

Dear All,

Im experiencing a little movements on the 2nd bank of faders (i.e. bank 9-16). I'm noticing that every now and then a fader set to 0.0 will move on its own to -0.8 then it might move again lets say to +0.2 then to +1.0 etc. This happens on 3 faders on the same bank (fader number 10,14 and 16). THERE IS NO AUTOMATION ENGAGED. This happens when the mixer is idle and also when in operation.

Any help please?

[Phil.c]

Try a fader calibration?

[Carlo]

I did that for 5 times but it seems it does not help.

[Carlo]

Has somebody ever recapped the a fader bank?

[Jondav1120]

Hi Carlo,
Presumably the faders move on the GUI as well as the desk? All three faders started doing this at the same time?
I'd suspect something in the fader motor drive circuit (see picture). Either leakage through Q2/3/4/5, rail caps C1 & 2, or possibly a flaky op-amp (U2A).

[Carlo]

Hi

They do it independently sometimes separately and sometimes 2 faders together etc seen both on faders and GUI. I replaced the fader bank with another old bank that i had in reserve and it seems that its happening again but this time its very little compared to the bank that i had before. I recalibrated numerous times and i noticed that when the mixer is at UNITY level some faders do move very little even on other banks. The movement is barely noticeable i.e. +/- 0.2 but not all faders do it.

[Jondav1120]

Hi Carlo,

Another thought......do they still move if you turn the fader motors off?

[Carlo]

No they don't if i switch to faders off

[Carlo]

I have another d8b. Its spot on and faders does not move

[Phil.c]

If you replaced the bank and it still happened then it's not the bank, just to check, move the faulty bank to either 1 or 3 banks just to see if it still happens.