To diagnose the problem try trial and error to narrow down the cause of the issue. These instructions serve as a guide on what to try to narrow down the problem:
1. Inserting a battery from another (same model) laptop that you know is working, if it does then the original battery is faulty and needs replacing.
2. If not then try with just the cable attached, remove the battery to make sure the laptop isn’t faulty itself.
3. Should the power supply not work try with a different power cable, this can be split into 2 parts so can be interchanged with the one that isn’t working to see if it a specific part of the cable
4. If the battery and the power supply work on another laptop then the laptop needs a replacement motherboard.