Could there have been a discharge pulse of static electricity, that has damaged some component in the computer?
You should try hitting F9 (once) when the system comes on to see if you can start Recovery Mode.
Also, if you have the Intel NM10 chipset (you probably do), the maximum RAM is 4GB, but only in a 2x2GB configuration. A 4GB stick won't work.
So i need a new motherboard !!
Someone have a eee (1015PED) with broken screen or keyboard... but the motherboard are ok, i'm interested to buy... !
It's a good idea to ask here, and check some web sites where second hand computers are sold, for example Blocket. There are also several companies selling second hand revamped computers at reasonable prices.