|Normally on modern devices the case should NOT have any bonding to ground.|
All mains powered electrical equipment with a metal case should have the case bonded to ground. It is safety thing so if there should be a short circuit to the case the current goes to ground and reduces the chances of an electric shock. That is what the third prong is for.
Having the case bonded to earth will cause a fuse to blow or an RCB to trip. If the case were not bonded to earth, anyone touching a live case will get the full potential of the electric current right through them.
Most domestic appliances, like computers and audio equipment come under Class 1
Class II usually applies to portable appliances like power tools and requires double insulation. Computers certainly don't have double insulation.