Hi,
Have you tried doing a test with the AC adapter and battery itself?
- Remove the battery off the laptop then connect it directly to it's AC adapter and see if it will boot up or not.
- If the laptop will boot up with just the AC adapter connect that means it's still working properly and it's the battery that is faulty.
- But if the laptop will not boot up without the battery and just connected to the AC adapter then the problem may lie in the AC adapter.
- Do test a different AC adapter that has the same voltage and see if it will work or not.
- If it will still not work, the problem lies inside the motherboard.