Is it in warranty? If it is, contact Acer. If it's not in warranty, remove the battery and wall power, hold in power button for about 30 seconds, plug in only wall power, see if it turns on then. Any lights or beeps from the system when you try to turn it on? Does the charging light go on? Can try another power adapter. Remove all the RAM, does the system give any error peeps then? If not, that is a good sign the motherboard is bad.
Another thing you can try is to take it apart, remove the CMOS battery if it's removable, and hold in the power button for 30 seconds then, with main battery and wall power out of course.