Why are receivers not grounded (earthed)?

[MrMik]

My Pioneer VSX-930 has no ground pin where the 240V cable gets plugged in. I get mild electric shocks when I touch the screws on the housing while standing barefooted on a concrete floor. My multimeter measures 120V AC between the screws and ground.

 

[americanaudiophile]

Some receivers leave out the earth connection to avoid ground loops which would cause continuous hum and buzzing noises. You definitely have a problem if you get 120v to ground. Contact Pioneer and they may suggest grounding the receiver or it may need service.

 

[MrMik]

Some receivers leave out the earth connection to avoid ground loops which would cause continuous hum and buzzing noises. You definitely have a problem if you get 120v to ground. Contact Pioneer and they may suggest grounding the receiver or it may need service.

Thank you!

I have called the shop (I bought it just a few days ago) and they are getting in contact with someone. A tweeter in one speaker is also not workiing.
Meanwhile, I'm powering the receiver through an isolating transformer.