Richmond Exposure - Odd Sound

[1964GN]

We have a Richmond Screenmaker SM3000 exposure unit that is starting to do weird things. The loud sound starts cutting in and out (it starts about 1/2 through the video. It seems to be getting worse. Any one have an idea what is wrong with it AND does anyone know where you can get parts for this thing? We have a new bulb but are reluctant to use it until we figure out what's going on

https://www.youtube.com/watch?v=qISDlf16Ltg&feature=youtu.be

[3Deep]

Only moving parts that would make a sound are the cooling fans and vac motor, if you have any fluorescent lights in there then it could be the valance making noise and going out.

[1964GN]

The noise cuts in and out regardless if the overhead ceiling lights are on or not. It's not the vac motor or fans. Maybe a spark plug issue?

[Northland]

To me.... it sounds like the contactor (relay) that turns either the vac motor -or- lamp on.
It has a movable armature and electrical contacts that can get dirty/pitted.

Turn the power off.
Most contactors have a removable plate that will allow you to get at the contacts to clean them and the pole faces.
Try blowing some air across the contact area.

If it is a bad contactor.... you should be able to find a generic replacement (wouldn't have to come from Richmond.
It would look something like this:
https://www.google.com/search?q=2+pole+contactor&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjZk5vDj5rcAhXsy4MKHbn_AC0Q_AUICygC&biw=1093&bih=530