One USB port in the laptop is loose and stopped working. When you plug a USB device into this port nothing happens, it’s not detected by the laptop. The same USB device works fine in all other USB ports in the laptop.
1. Bad connection between the USB port and motherboard.
2. USB port broken.
Possible troubleshooting steps and repair solution:
1. In most laptops USB ports are soldered directly to the motherboard or USB board. If you use USB ports a lot, overtime the solder joints between the port and motherboard can get cracked and the port loses contact with the motherboard. That’s why it feels loose and the USB device plugged into this port is not recognized. Resoldering the USB port might fix the problem.
2. The USB port could be broken. You’ll have to replace the broken port or use only remainging workng ports.
If all USB ports are broken and you don’t want to spend money fixing them, you can buy a PCMCIA USB card. You plug this card into the available PC slot in your laptop and get 2 or 4 USB ports.