Neal, I have the exact same problem as you. The unit powers up (standby amber), press to power on and it goes to blue, but no display and doesn't work.
I'm not trying to hijack, but want ride along to see if anyone can help with a fix.
FYI,... I've taken mine apart and disconnected the display circuit brd, power supply brd, and no change. I also tried to force a code load via USB but it failed, however, my PC did recognize the Sherwood as a device. I did a processor reset (from standby, press and hold room2 + tone mode then power up), which you may want to try as well.
Also wondering if anyone knows how you unlock these processors.
Thanks