Hold down the power button with ten seconds. :-) This boots/reboots the BV6000 in 'normal' mode. The problem is that the recovery.img is broken after the OTA updates from October (201610xx, 20161025). These OTA updates do not have an updated stock recovery.img whereas the updated system itself uses...

Seems to be.
I got the usb - replacement board in december via mail. The replacement action according to the youtube viedeo wasn't very difficult.
And it works now like a charm

ABEF

and if possible a smaller size factor !!

also after updating to the newest ROM the compass is still not reliable /usable (+/-120°)

Re-Calibration works (or seems to work) - at least it shows a "success" note,
but 1 second later the next note pops up with "The accuracy is low Please to calibrate compass"

Best Regards