It's probably the power supply, I borrowed this from another thread:
Fry's has a few different things that will work. The particular one I decided on is called the Rhino 2500mA AC Adapter. It's labeled for use with digital cameras, but will work fine with the box using the largest included tip and the 5v setting. It's also important to install the tip in the "center positive" orientation. The instructions cover how to do that.
Here's the Fry's product page for it... http://www.frys.com/product/5249157
I bought a used Cisco 34-0912-02 power supply and it works great.
Tip and polarity work without modifications
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0196748671