I replaced the power supply in my Dell PC with an aftermarket one (Athena brand) of higher wattage and once I installed it and connected everything, without pushing the on button, as soon as I plugged in the AC cord, the power light on the on button came on and horrendous noises which sounded like the hard drive clicking and whirring started right away. It could have been the PSU fan making the noise but it sounded more like a hard drive but real fast whirring and real loud clicking. I immediately unplugged the AC cord and reinstalled my old power supply. The PC started up normally and I had to push the on button to get it to start up. I bench tested the new power supply by plugging it into an AC outlet and the blue light on the back came on but nothing else happened. I was under the impression that the PSU fan would come on in this case but it did not. Does this point to a bad power supply or something in my installation? I am tempted to return the new PSU but I am reluctant to buy another one if it could have been an installation problem.