Press the F12 key when booting up, you will get a menu that will let you check the BIOS or run diagnostics. In BIOS the ac adapter and battery are at the top of the list. If the ac adapter shows as 1 watt or unknown then the problem is either the ac adapter or the mother board. If the battery does not show up then it is likely a bad battery. Run diagnostics to test the components, if the battery is bad it will show up as weak in diagnostics. Diagnostics will test the fans, CPU and memory.