I have a late 2009 21.5" iMac. The problem is whenever i plug in the iMac i see a blue spark from the inside the Mac and a loud bang sound. This causes the MCB (Miniature Circuit Breaker) to trip / fuse to blow. There hasn't been any power issue in the circuits in my house, this started happening suddenly. I hope its just an internal power problem and nothing too serious. Can someone tell me what exactly the problem is? Thank you.