My friend has an old crappy Emachines 3200 and the won't even turn on now! When i slowly insert the power plug, it will turn on/off very suddenly and make a crackling noise?? At the same time the cpu fan will turn on/off for 1 second and that's it. Also, i can see a green light come on the motherboard too. Before all this happened she told me the hd made a awful loud noise too. Do i need to get another power supply then or is the whole motherboard gone? Any help would be great.
Yup, sounds like the PSU blew.
You can try replacing it but there is no guarentee that it did not take everything with it. You would probably be better upgrading to a new machine and trying to salvage the old hard drive.
Slowly inserting the power plug into the PSU is a pretty darn stupid idea. Like this you make sure you get arching and powerspikes, making certain the PSU dies. Furthermore I would'nt be surprised if you at least killed the MB along with the PSU like that...