I have an issue where my Avalon 741 is only hashing at around 3.6TH for some reason.
It is running off a Bitmain 1600W PSU so that is not the problem.
~
You'll probably want to ask here:
https://bitcointalk.org/index.php?topic=3224256.0, the A-721, -741, -821, -841 Support thread.
I will suggest that you should try another PSU. That one
may be defective.
Mine on!