Unresponsive computer i have a gateway computer that does not work, it does not respond to the power button and only responds to unplugging and plugging in. when u plug the machine it the fan and HD automaticlly beging working but that is it. the light behind the power button does not illuminate but the HD light does. the only way to get the fan to shut off would be to unplug the machine. this is all this machine will do

If the power switch on the case is shorted out. (Not uncommon), you would get this kind of issue. There are other issues going on here. You should be getting a video display, from what you said your not. That is more of a concern. If you can borrow a PSU & swap yours out that would help. I see no need to buy one because that may not be the root cause for this system. You need to get video. There is a togel switch on the back of the PSU. You do not need to unplug the PSU, just click the switch. There also is a red switch on the PSU. Make sure it is set to 115v. Get back to me here after you try the swap. Best of luck!