polymer_city,

Try lowering the frequency using ssh or with GUI as soon as you power it up since t works for you for a little while.
The factory setting will run the miner at 250 and in my case it just didn't work.

In my case GUI wouldnt show up at all when miner was received so I had to do it using ssh.

Once frequency is lower, GUI may start responding.

I had to lower the frequency to 218.5 to make the GUI and miner work. Eventually I had to bring it down to 193.5 to keep it stable and consumes 660 watts for .7 Thashes . Temperature stays in 40s so cooling is not the issue.

I am not sure why bitmain is not accepting the reality of situation and offering a solution to this problem.