Hi, my Toshiba Satellite works from the mains, but the battery is down to 0%. Says it is plugged in, not charging. Does this just mean that the battery is done or is it a technical problem with the laptop itself?
It could be the battery is in need of replacing, or it could mean it isn't getting power.
Try turning the laptop off (completely powered off, not sleep or hibernate) and then plug it in to charge. If it will charge while the laptop is off, then the problem is likely the charger and not the battery. A sign of a charger going bad is it is unable to charge the battery and run the device at the same time, so it will only charge the battery when the device is turned off.
However, if it won't charge the battery even when the laptop is turned off, then it is likely the battery needs to be replaced. Just be sure you get an OEM battery and not an aftermarket one or you can run into even more problems.