Percussive anti-maintenance
A word of warning.
Way back in the day we were fitting a replacement disc into an external drive for a Sparcstation IPX.
The disc was hapilly formatting away and making the usual happy burbling chirpy noises.
Old style engineer walks past, says "Fan's sticking." and gives the drive a good slap.
This (presumably) caused the heads to bounce around on the platters which is not in the best interest of further use.
Fortunately we were able to find another replacement drive.
Engineer spent some time looking very sheepish.