Display problem. my laptop ( compaq preserio v2036AP) display goes off suddenly... screen gets

Question

my laptop ( compaq preserio v2036AP) display goes off suddenly... screen gets blank...even pressing keys on laptop doesnt solve the problem .. i have to restart the system.. and this happens anytimes sometimes with in few minutes or some times after few hours.. somes once in few days... also i have noticed that my cpu fan never works ( right from the day i have purchased) could this be a problem ..... kindly suggest.....