Sony laptops rarely have usb problems. However you may have plugged a usb pen drive or broadband dongle into the usb port. Sometimes the port can get damaged by the dongle or pen drive. Inside the laptop the usb works with 5 volts. There are 2 data points and 1 positive and 1 negative. 4 points alltogether. The usb ports are quite easy to repair you just need to desolder the broken port and replace it with a new one. The big problem is when the usb suffers a short and blows the chipset. The sony laptop will in this case need the motherboard replaced.
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