Has anyone experienced a vibrating Komo mill?

I was looking forward to picking up my ‘new’ used Komo Medium flour mill today from a seller. I just found out it hasn’t been used in a couple of years (it’s 7 years old) and when they turned it on it is vibrating. Has anyone experienced vibrating with a Komo or Mockmill? In the meantime the seller is trying to find the receipt (it is lost) because technically it is still under the 12 year warranty. Any suggestions or ideas would be appreciated. Thank you.