Due to a mistake late in the day, the power off transistors for three LED groups are not working (T801-803). Solder 0 Ohm resistors there and disconnect the battery to power off the badge (otherwise, the LEDs are consuming 0.5 mA in stand by)

I've heard this happened with ~10 new devices, but mine also went black the next day (cxcv). This bug(?) appears on all devices at the same time but not all the time. on 2015-08-13 11:00 It worked, 2015-08-13 15:20 it went black again for the hackrf firmware. (f0086) Talked to the supporters, issue is related to power supply and they are working on a software fix (cxcv)