Hi
Can your laptop run on mains with no battery?
If so then plug on charger and socket in laptop is working
If not may be fault with socket and connection to motherboard, possibly needing re soldering
If motherboard has a charger fault then some specialist companies can repair the motherboard
You are paying for time of diagnostics, removing motherboard from case and then repairing then refitting so for old low spec laptop may be unecconomic to repair
If so sell for spare parts and buy a new one
Regards
Mike Barnes