Start up problem with acer aspire 5112

Hi, sorry that my first post on this forum would be a cry for help, but i've no clue what to do.

I bought a acer aspire 5112 a year ago and now this last week I started to experience blue screens, and sometimes the computer just freez and I have to force turn it of. Now this morning when I started the computer, all that was happening was the computer turned on but no picture, just the sound from the computer. Also in 1/20 tries the screens actually turns on but the computer freeze at the ACER screen in the beginning. I have no clue what to do and my Warranty just expired a month ago, so please need some help.

I dont know what specifications that is of value in this quest for life of my computer, I havent changed anything from the original specifications, beside I got the computer with win xp -> upgraded to win vista (bios and other things taht was included in acer uppgrade package) -> fresh install with win xp again (vista was to unstable)

Plz help!!! Any idea of what is happening with the computer is welcome!

//Zapmore