Hi,
Here are some troubleshooting steps that may identify which one really is faulty.
- Start by testing the AC adapter if it's still supplying enough voltage to power the laptop or charger it or try another AC adapter that has the same voltage to power the laptop.
- Next is to remove the battery from the laptop and boot it up with out it. If it will not shut down that means the AC adapter is working properly and the battery is faulty already.
- If the laptop will still shut down without the battery that means it can be something else inside the laptop. (motherboard)