Yeah the S9K is the only one that you can't flash Braiins OS onto and it doesn't seem to like non-stock fans either. The Noctura fans that I put on it are almost as fast RPM as the stock fans but with those ones it's rebooting constantly. With slower fans the red fault light comes on and it stops hashing.
Discussion
Hey man, I just had a constant reboot issue (maybe similar to the one you described) and was able to fix it by setting the fans to manual. Have you tried this? 