March 25, 2011
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A few days ago, I was using my work Secure USB storage device ( stick / pen drive, whatever you want to call it) and I accidentally put it into a Window PC with a faulty USB port.
The PC in question was under a users desk and the user appears to have been kicking the front of the box, causing the plastic structure of the inside of the USB port to become broken, exposing the connectors and bending them out of shape.
When I connected the USB device to the PC it corrupted the device, I assume that the connectors passed incorrect voltages over pins that are not designed to accept such voltages.
After realising this, I tried the device on another Windows PC and received an error advising of a power surge on the USB port interface and that the device had been deactivated (at least there is some sort of integrity checking).
Interestingly I was asked a few days later to investigate a fault on an Intel iMac which was experiencing faults with an interactive whiteboard connected to it. A colleague had already looked at the issue and upgraded the firmware on the machine and I upgraded the drivers and the software for the interactive whiteboard but the iMac was showing an error on login “USB Over Current Notice: A USB device is currently drawing too much power. The hub it is attached to will be deactivated” .
Because of my earlier experience with the PC I checked the USB ports on the iMac and found a broken port where the connectors were touching the shielding surrounding the port. It appears that the power sent through the pins were being transferred to the other pins, and presumably the earth, causing the error. As the site did not have the funds to have the machine sent for repair, I carefully moved the pins using a watchmakers screwdriver so that they weren’t touching the shielding or each other and then taped off the faulty port.
The iMac is now running quicker ( which makes sense as it’s not having to deal with a hardware fault) and the users are now aware that they have to be more careful when connecting USB devices so as not to damage another port.
I hope this information helps someone else in a similar situation.