I am really glad I ran across this post.  I have 2 s5s.  the controller board went bad on one.  I simply turned them both on their side toward each other, then connected the data cables and the fan on the bad s5 to the controller board of the good controller board and walla!!!!  4 boards running at 59C and clocked at 400mhz.  Thanks a great deal guys.  Probably never would have tried that without seeing this post.