The most common reason we hear is that the Xbox has been dropped or knocked while plugged in. This causes the cable to yank out and physically damage the port. It can also happen while plugging in the cable. The ports are quite delicate so if the cable isn’t plugged in carefully to the Xbox 360 it can cause damage.
How do we repair the Xbox 360 port?
To repair this fault we need to carefully strip the console down to the motherboard. From there we desolder the old port. It is a delicate job. Once the old port is removed the solder pads of the logic board are inspected for damage. If the original port is really badly yanked this can cause damage to the motherboard and in some circumstances could be beyond repair (although that is very rarely the case).
Once we have cleaned up the board and prepped the solder pads for the new port we solder the new port into place. We reassmeble the console and it goes down to our testing bench where all consoles are tested for at least 4 hours.