I have an old XR886 mixer that I recently bought as a spare mixer. Everything works perfectly on it except the effects.
The signal from each channel reaches the EFX master send potentiometer. I can see this from the fact that the signal appears on the output indicator using the PFL function of the EFX. But neither the master return nor the mon1, mon2 potentiometer does not send a signal to the main mix or to the monitors.
Based on the user manual "When the new effect is selected, it causes the PFL/CLIP LED to blink to indicate the effect is loaded". In my case, the LED does not flash, when I am changing the program.
The effects processor seems to be dead.
If anyone can help or has an idea what the problem could be, I would be very happy.