but I will do the best I can for you
give me a minute
I would replace with these two fans
https://www.ebay.com/itm/NEW-Delta-EFC1212DE-120mm-x-38mm-Fan-12V-DC-4-Pin-Connector-Made-In-Thailand/112043486249?
these are four pin but will not go to 6000 rpm at full speed they go to 4000 rpm
these could be okay
https://www.ebay.com/itm/Used-Delta-fan-AFB1212VHE-12V-0-9A-case-cooling-Fan-lots-of-5pc/193217342422?
look here for 4000 rpm models
https://www.delta-fan.com/
you have these
https://www.ebay.com/itm/Antminer-S9-S7-D3-L3-Fan-12V-2-7A-6000-RPM-120x120x38mm-4pin-Delta-QFR1212GHE/162947503113?
they will do 6000 rpm.
as for fixing the firmware try asking in altcoins
I asked mods to move to alt coins
Thank you for that, i never did think of just putting slower fans on there, but would a surge ruin the fan? or what would cause it to no longer idle down the fans like it use to