For some reason my surge protector gang plug has started to intermittently crackle. So I bought a new one, same issue. Through elimination I found it was only happening when PC was plugged in. Bought new power supply, same issue. I read that the front panel USB can cause power spikes or surges, same issue. I am at a loss as to proceed, maybe removing components and trying. The PC only has to be plugged in, power switch on but PC not running for the crackle to happen very intermittently. I have swapped leads, unplugged everything apart from power cable (which I have also replaced), still no idea. PC can run all day and no issue, or a couple of hours then a reboot then fine again. Any ideas please would be a great help.