I've left it in my glovebox for about a month or 2 and now its not turning on, i've connected it to my car and to a computer and its not turning on. Anyone have any ideas?
I was thinking damage to the USB port but the computer plugs into a different port than the car. That leaves something within the AP itself. Perhaps the screen is not working so you can't confirm it is on.
The same USB cable is used for both set ups. Maybe something is wrong with it. That would be simple to check if you could borrow another cable. Short of that I would contact Cobb and ask them directly.
I had the same issue 2 weeks ago, so I send the unit back to them and they said there was something wrong with the main board on mine, and sent me a new unit under warranty and replaced the dongle as well. Mine now turns on but I am not able to get it to communicate with the ECU. So I'd recommend calling them to see if you can get a RA # and send it back for them to check, and hopefully replace for free.
If you get a whole new unit you would lose you stock map as it is stored in your AP. Since the AP is married to your car I'm not sure what would come from a new unit, as in what problems you would encounter. I guess you have no option but to send it back and hope they don't tell you it is not covered by a warranty.