Is it under warranty? If so, make it Acer's problem. If not, start looking for a new laptop, because all the possibilities for fixing this are going to be a significant portion of a new laptop.
FWIW, I would recommend against Acer (and it's other brands Gateway and eMachines) as well as HP (and it's other brand Compaq). They seem to have a disproportionately high number of hardware related problems. Just my opinion based on years of observations. Take it for whatever you will.
I have an Acer laptop (AMD athlon dual core, 1MB ram, vista) that won't boot. I've had this problem for about a week now, and it's driving me crazy. I've pulled out the battery, held down the start button, then tried plugging it in and restarting...no luck. I AM using mcafee, but I thought that was XP computers only....When I try to start it, it powers up for about 3 seconds, then shuts down. No BIOS access, no safe mode, nothing.