I have bricked a S3 with an improperly downloaded frimware upgrade, does anyone know if there is a way to reflash the firmware or to do a hard reset (holding reset button did not work) without being able to access the GUI?
Maybe some info from this thread could help you out:
Taugeran's Antminer S1/S3 revival story guide -
https://bitcointalk.org/index.php?topic=775662.0