My computer recently had a failed fan in the power supply unit. I took the machine to an official computer tech company and they replaced it. I brought the machine home, used it once. I turned off the machine, unplugged it to use outlet for another computer. I then replugged in the machine with the new power supply and nothing happened when i turned on the machine. Nothing, nada, zilch. No noise, no video, no nada. I see a green light on the chip board inside the unit so i know its receiving power, but no Action. Is this my motherboard now, and maybe my processor. The tech's say that i need a new motherboard and processor. But i dont trust them anymore after my replaced power supply and now dead computer. Any suggestions on the logic of what's happening with my machine? PLEASE HELP. I'm an end-user, not a tech...so I just need this all to make sense. Thank you!