There are EMI or RFI type emissions present in your area of operation. For whatever reason, you have been compromised. You can best "shield" the computer or move it from the offending source, whatever it is. You may still have AC line problems, but only a electrician can sort that out should you care to.
As a test, use a long electrical ext. cord, have system outside and then power some item in the kitchen. That way, because you're still connected by cord, the AC issue maybe at fault. Your system is far away for emissions to be at fault, unless very powerful.
hi....... been using pc in the kitchen for 5 years. this last 6 weeks, every few minits the screen vibrates and you cant make out writing etc, playing games is a no no . thought it was the monitor going west , so just put up with it, yesterday i picked up another monitor, all was well till my daughter put the kettle on, and hay presto screen vibrated, so.. changed vga card. still vibrates, changed power wires from pc to mains, after alot of hair pulling.....i changed pc for a spare 1,
the outcome is.....anyware in the kitchen....if something electrical is switched on. the screen vibrates. i even used a long lead from another room, so that im not using pc on the same curcit as all the stuff in the kitchen...........but still got a vibrating screen..........
any ideas would be greatfully recieved,...............cheers