Hey there!
I've been searching the web all day and this forum has come up often.
I recently acquired a Minibrute that had a malfunctioning arpeggiator switch that was stuck in Up mode when set to Up/Down and Random. I was told to update the firmware instead.
I downloaded the newest firmware, connected the device, and attempted to install. The update froze partway through and failed. I attempted to reboot and got the 5 LEDs on the octave switches lit up. I tried running the firmware again but it wouldn't see the device this time.
So, I followed the steps of powering down, holding the octave switches, and trying again. Still nothing. I tried this dozens of times and nothing has worked.
I tried finding the older Firmware in case there was an issue with making the jump. So, I downloaded the older version of Brute Connection and the Firmware (1.0.2) and tried the same thing. No luck. I followed the steps again to click cancel when the device could not connect/be seen, attempted to manually upload the firmware by clicking the Firmware tab and the update button. Nothing.
I tried different cables, different ports and different computers. Nothing works. I'm currently attempting to run on OSX El Capitan/10.11.6
I've even tried rebooting after removing the device from power, with and without holding the buttons. At one point I managed to get it to power on with a single LED lit (the LED for -1 octave) but even still, nothing worked.
As it stands, the device is totally unresponsive. No sound, no other LED response or key response.