My laptop is dead,help?

i was installing my bios to previous version on my hp pavillion laptop and the laptop was overheated and i had to restart my computer and now the computer does not show any activity on the screen ,just blank,when i press the funtion keys nothing happens.even putting ther booyable cd n the drive doesnt help .the lights of the touch ons only come .and the caps lock and num lock lights flash.the computer is dead ,plz help me .it is under warranty.i feel the bios was irrased as the process bar had reached mid way .any way to install the bios ??will they replace hte unit