I got a CANxtra recently. When I open the back cover, CANxtra does not boot. When I put the back cover, CANxtra boots again.
Please let me know what is going on here.
Very strange!!!
Hidden tamper switch 
OOpening the case?! There goes your warranty.
I got two CANxtras. One worked fine, other didn’t work at all. I opened the case and tried it didnt work either. Then I closed it, it started to work. I loosed the screw half way and tried. It didn’t work at all.
The screws need to be tighten fully to work. I cant understand what is going on.
must be a bad solder joint somewhere
You may want to contact GHI directly for an exchange.