The Netduino forums have been replaced by new forums at community.wildernesslabs.co.
This site has been preserved for archival purposes only
and the ability to make new accounts or posts has been turned off.
You have to hold down the button on the netduino while you are plugging in the device. You did not mention if you were doing it that or not. This and rewriting firmware has always brought my devices back from the dead.