I also have had this problem while attempting a firmware update of my Andromeda, which I'd like to share, perhaps to simply warn off people from attempting to upgrade beyond the warranty period.
Right now my pedal is completely dead, it wont power on and there is no official documentation available even on SD website, some posts around here suggest pressing the little hidden button while powering on, even that seems to not work, tried with 3 different power supplies.
It's worth mentioning now that this has happened before, some months ago, at that time I took it to my dealer and they sent it away, it came back functional but it didn't seem to work the same, I think it maybe had regressed to a factory setting and perhaps originally it had been sold with the latest firmware (it had better, less choppy response to delay time changing).
anyway I might have to take it back again but this time I want to know exactly what that repairman did to reset it, maybe they have to flash the bootloader from an internal header or something, this time I will require it to be with the latest firmware installed.
seeing that there are others with this issue I think that SD hasn't made the firmware update robust enough, the bootloader has to be bullet proof, sure it's a rare problem but I suspect most people will never attempt a firmware upgrade.
Upgrade error message:
Timed-out waiting for bootloader. Please
disconnect and power-cycle your Andromeda
then restart the update process.
[App:v1.03.003.0.master.20190220115552] [Sys:Mac_OSX_10.16x64] [Ram:16384mb] [Cpu:12x2600MHz] [LastActive:andromeda, 0017SYRSF02002024, v1.02.034.0.master.20190102170416]