- Test output voltage of AC adapter or test it in another (similar laptop).
- Test battery in another (similar laptop).
- Test CMOS battery and replace as needed.
Also Try to:
- Startup on battery only
- Startup on AC only
If symptoms persist or if this has been done...
Try the steps below:
- Power OFF the computer
- Remove the battery
- Unplug AC
- Press and hold Power ON button for 30 secs. at least
- Put back the battery
- Plug back AC
- Power ON as normal
If the same thing happens...
- Take it apart/Disassemble the laptop
- Remove the rest, except RAM, mobo, LCD and power ON switch
- Power ON using adapter