Thanks for your replys A magnet will stick to it :) And when you put the magnet near it while its on.. it will go louder.. The noise also makes my speakers produce a similar sound. I have also tested the voltage on the power supply, it seemed to be at around 32v, when I tested it while it was plugged into the router the voltage changed every so often, when the squealing stopped the voltage went upto 31.05 when it squealed again it went down to around 30.50? What could be at fault?