I hope your mobo isn't dead. I had one die and never found out what happened to it or why it fried. I'm not saying it is, I'm not a pro. Going by experience of my own. There's usually more than one reason that something can go out with pc's so rest assured I could be wrong.

It does sound like something is out now though. Did you ensure everything was connected properly with the new psu? Right specs (same kind that was in it?)

The one I had that fried I replaced the psu 2 times until I found out. Once I replaced the MOBO everything was ok. If you have a back up mobo, it may help to try it.

I'm not familiar with EMachines but I'm thinking they run the same pretty much?

Hope there was some help in this message for ya.
Xts

i have almost the same problem except that i can hear like a wistle sound coming from instide the computer other then that no funs, no lights are on exept for the motherboard light. and all you can see on the screen is black no bios no noting. so please help me

Maybe the CMOS battery is dead(empty). If I were you i'd try to replace it and maybe (it's only a couple of bucks).

Good luck.