You realize that ancient relic of a DBV is about 20 years old right?
It may have the driest , oldest belts and gears on earth....look at the oxidization forming on top of the DBV body.
Was it stored in a damp area?
It needs to be taken out, fully dis-assembled and cleaned like it probably
hasn't been done to in years.
Take pictures if it helps you to remember how it goes back together!
Use mild soap and warm water only.
Re-assemble and carefully put it back into the machine.
Never dis-connect or plug in ANY connectors around it with the power switch on.
Good luck and let us know if you run into any problems!