Any ideas?
Did you try both fan connector? And if they're both dead, thats pretty weird, but your only option then is pretty simple, you're going to need to power the Fans strait off the power supply. You would ideally get a controller so you can control the fan speed. Otherwise they're going to be running full speed at all time. But if thats fine with you...
Will it hash if it doesn't see fan speed?
Oh, i see what you mean. It may have a protection where it will just beep if there is no RPM detected on Fan1. I do not know if there is a hardware or software workaround to override this protection, if it is active on your miner.
But you said it would try to mine and overheat, therefore it is not?