When I plug in my computer the computer works and shows that it’s charging but when I disconnect the charging cable the...

This sounds like the cooling system isn’t functioning properly. Check to see if the fans are turning on properly. After turning on the computer wait for the device to start heating up. Then check the bottom, back portion of the laptop to feel if air is being blown out. If no air is blowing out the fans are not working properly, and you can try replacing the fan assembly. Also, check out the troubleshooting page for further help.