i have read quite a lot about this and i would like the experts opinion. I have an old dell desktop with a 250 watt PSU - PSU is grounded to the metal casing of the psu and the psu in turn touches the metal part of the PC case. I brought the PC from UK to Vietnam to be donated to a home. I noticed that since i am in Vietnam, the case is live / if i touch it, i get a tickle and if i apply a test pen, the test pen lights up. I also noticed that most wall outlets are not earth at all (most sockets only have the live and neutral. 1. Is it safe for me to use the PC (even though users touching it will get a tickle. 2. Do you that the capacitors are faulty (the ones leaking current to the body? (They are blue Thank you Michael
Short answer, anything with a metal case that is not double insulated should be grounded for safety. A live to earth short circuit fault inside the computer will create a life threatening condition. Make sure the supply is fused and install a ground rod connected to the supply outlets ground connections.
I experienced exactly this condition in Portugal which is supposed to have European standards on electrical installations. I was getting a tingle from the metal screens on the speakers of an old laptop. As has been pointed out this is low current and not harmful itself. It is however a warning that all is not safe with the electrical installation.