I have a DR3 and unfortunately I didn't know about it. In good faith, I (although there was no reason) upgraded to the November fw. It is functional, but does not allow to reduce the fan speed. I will never give a new bitman's shit fw for no reason.
Is there any new solution to get older fw into DR3? Or via SD card? It never worked for me on another Antminer. In addition, there are no jumpers on the DR3 control board for switching to the SD card, and I didn't find anything about that on the net.
Thank you!