I have an issue while trying to downgrade my S21.
Some days ago my S21 stopped to recognize some chips. I think it's a problem with some of the hashboard and I will need to find someone able to fix it here in Brazil - and that's a tough thing to do.
I had an idea to install the vnish firmware to force it to run without one of the hashboards but I have the latest firmware installed - FR-1.12(251009-S21).
I did download of the version for "unlock" the ASIC to get it able to receive the vnish firmware. I did it to a formatted(FAT32) pen drive(8 Gb) USB2.0. I boutgh an OTG Cable(bought 3 types of it until now) to plug it into the ASIC, but when I do the process to downgrade, it simple doesn't run.
I have tried to change the pen drive model, OTG cable model and even the sites where I download the firmware, but it doesn't work. I turn the ASIC off, plug the OTG cable with the pen drive and then I turn the asic ON. After that the ASIC just run as it was without the OTG cable. Doing a normal initialization.
Have you ever happened to you?
I don't know what to do but I really need to put this ASIC to work.
Wish someone help me
Thank you
you need a new controller.
my sponsor altairtech sells the epic controller.
it will let you use 1 ,2 ,3 hashboards. it will also let you under clock a bit.
my signature links to their website and I would get a fee.
or this link directly goes to the controller you need to use.
https://altairtech.io/product/epic-umc-universal-mining-control-board/get the one for s21
whether you use my referral or the direct link this is likely what you need to do as new bitmain firmware locks the controllers .
good luck