If you leave the laptop charging does the battery charge indicator LED ( light ) ever change from orange charging to green fully charged status? If it never makes it to green it could be a bad battry that wont take a charge. If you charge it and it finally goes green, keep the as adapter plugged in and try to power up laptop.
Also, have you tried powering the laptop up with the ac adapter powering it with no battery present. ( a friend showed me that his laptop could actually run without battery direct from ac adapter, while I didnt think this was possible, on his model it worked.) He had a bad battery pulling down the ac adapter, so there wasnt enough power to power the laptop, but removing the bad battery load from the equation, it powered up when powered from ac adapter direct without battery installed.
Also any additional info would be helpful, such as if it was acting up prior to this final failure, was the battery life not so great to show that the battery may have been on its way out, or was this laptop involved in an accidental situation of dropped, drink spilled on keyboard, ect.
