Quote from: thecryptoprick on August 01, 2018, 02:51:23 PM

The S9i runs fine on one hash board, I tested both PSU's. When I power two, this time instead of getting the red fault light and fans slow down. I get one of the PSU breakout boards blinking, i.e., the digital voltage readout blinks, also the PSU green LED blinks.

Are those breakout boards linked together? Not sure about parallels break out boards but other setups that are similar to this such as a 750w + 1200w psu can be used to power an S9. No need to link the breakout boards. I use the 750w for the control board and one hashboard and the 1200w for the other 2 hashboards. This sounds weird but the correct way to fire it up is to turn the 750w on first and then quickly following turn the 1200w on next.

Either way If both these psu's are 750w and you are running on 110v I would say thats not enough, your stressing the psus to much. They might be able to do it on 200+volt but even then I would recommended (2) 800watts or like I said a 750 and 1200.

Hopefully you get it sorted out and no damage to the machine occurs.