I got one for you, I have a tower that just the other night started "clicking" when powered on. It doesnt boot up or go to post or anything. The cpu and case fans wind up for a second or two then turn off and the tower just continues to make a clicking sound almost like it is hung.......I had this issue before and it had went away, had the power supply tested and it was good but changed it for good measure and here we are again. The weird thing is if you leave it plugged in it will work fine, but if you un-plug it and plug it back in it does this........I tested this new power supply last night and it seems to be fine as well. Anyone have any ideas? I am stumped!