My B1 got disconnected from power during our move…now it boots to a blank (but backlit) screen. No text is ever displayed on screen. It gets an IP address from the router but I can't connect to port 8001.
Main learning points from this thread are
1) use web interface to shutdown the B1. Having movers yank power cord while you are at work is not a graceful shutdown. I think this corrupted the emmc (which contains the boot OS). I finally have a good reason to get a backup power supply!
2) the micro sd adapter and the emmc don't get along for flashing (⅔ macs I tried didn't mount the emmc via sd). Use an external USB adapter that accepts microusb to flash the emmc. I succeeded in flashing the emmc with the sd card and sd card reader on a newer MacBook Pro, but it wouldn't boot. Flashing with USB adapter worked fine.
Minor points: booting to a blank white backlit screen is what happens when you have no emmc or the Os on the emmc is messed up. You may have a messed up OS and boot to a blank black backlit screen. That (i think ) means the Bootlaoder got loaded but then things pooped out. I also observed the B1 get stuck at log in (well, I didn't see it, my wife was hooking it up while I was at work and that was the photo she sent). Either way, re flashing the emmc is easy. Write speeds are about 20 megabytes per second and the image is 8gb ish.
I hope these little tidbits help others with cavalier shutdowns...I think mine had power cut off/on/off half a dozen times or so (don't ask…I wasn't there).