Our 18-200 VR (1) recently started making four faint thumps when the camera is turned on. Reading over posts here and other forums, this is either a complete disaster that requires hundreds of dollars of work, or completely normal and expected behaviour.
What the posts do have in common is they point their finger at the VR system. That leads me to my question:
How do you know if VR is working? Is there some sort of simple test I can perform?