[Dolbah]

I have VU meters in my 500 rack. I can assign them to the slots i want. 
When turning on the rack, the needle goes wild on both units for a couple of second (and they look in sync too)

There are no audio inputs to any of them.

There is also no sound comning from them.

I have switched slots, and this happen only with the EQs, not with any of my other units.

Here is a video, each VU represents a EQ-573-II module:



https://www.dropbox.com/s/wtkdhgeottkt38q/IMG_1192.MOV?dl=0

[Dolbah]

I measured the output of one of the unit, it reads a spike ove 3-4 VAC.
Since the needles on the VU meters are in what looks like perfect sync, i get a feeling they are supposed to do this, but need to be sure.

[JPK]

This is normal.
The circuits are single sided design and need some time to reach their DC idle state.