We have an issue with the Overo Gumstix when connecting to a Zytronixs USB touchscreen controller that isn't working.
 
We have modified a PCB and have changed the function of some of the pins could this have altered the USB output capability?
On power up with debug mode running we are able to see the USB being checked and found and during this time the LED on the controller flahses momentarily. After this it is completely shut down. The GumStix continues to function but there is no power output to drive the controller therefore nothing works and there is no power LED on the controller.
 
Any ideas welcome
 
Kirsty