If a LabQuest is not recognized by a computer that can see a different LabQuest, or if the unit fails to recognize a USB thumb drive, the circuit board in the LabQuest that controls both USB ports may be broken.

In this case, please contact Vernier technical support for a repair authorization.

See also:
My USB drive is not recognized by LabQuest. What can I do?
LabQuest with lots of data won't connect to a computer.
LabQuest won't connect to Logger Pro.