Is there a way to fire up the fans on the S9 for a period of time (let's say like 15 minutes) without any power running to the the hash boards (or even controller if possible)? I have an application where the S9s will be in an relatively external environment, and I want a safe way to start them up while ensuring there is no condensation when the unit is powered up. The condensation could occur after the units have been shut down and have cooled, and the ambient humidity has condensed. Assume I cannot have a back-up heater installed.
Any simple modifications anyone can think of? Maybe a small change to the firmware?
If you put in bad URLs for your pools you can fire up a unit and the fans will run, albeit at a somewhat lower speed, without hashing.
I use a similar technique in reverse to cool my Antminers before shutting them down. Specifically, I change the pool URLs to something wrong (by adding an 'x' character to the domain, for example) then hit "Save & Apply". The result is the miner software restarts, but can't get work from any pools, so the fans run without the boards doing any real work. After a few minutes the output from the fans is significantly cooler.
I have to admit that I don't know if cooling them down before powering them off provides any actual value. But with the insane amount of BTUs these suckers pump out it feels like just shutting them off while hot is not a great idea.