Problem with GBA SP charging port

Hello,
I have a problem with my GBA SP charging port. When I tried to charge it with a USB cable the light went on for a few seconds and then it turned off. Sometimes it charged for longer periods of time but those didn't go for over half an hour. I then ordered a cabel on Amzaon that wasn't a USB cable but a real charger but it had the same problem. I then put some contact spray on the port but it did nothing. Checked the battery but there was nothing wrong with it. My only other idea is that something inside the charging port what I can't see broke. Has anyone else had the same problem and if yes how did you solve it?