So my computer died out sometime ago, and not powering up I had initially thought that the motherboard was fried, so I replaced that today, but still no power, so it appears my Octigen 400w PSU is the problem, I tried the paperclip trick to test the fans but nothing, when I press the power button on the case I can see the fan will make a slight twitch but if I press again it wouldn't do anything, so it would only randomly make that twitch, is there any way i can repair my PSU or will I just have to replace it? many thanks.