Why you might wanna skip the Antminer T21

Sorry for the clickbait title but honestly, the T21 is a solid machine. That said, after using it for about a month, I've run into another issue (besides the 3-phase thing). So, it seems like if one of the hashboards goes down, the entire miner just stops working instead of continuing to hash with the other functional boards. I suspect this has something to do with the 3-phase power setup and needing the PSU balanced across the phases, but if anyone's got more insight, please share. Long story short, one of my hashboards is dead (not detecting any Asics) and now the whole miner is bricked. I tried updating the firmware but no luck, looks like I’ll be sending it back under warranty.

the epic control board from altairtech will fix that. you can run 1 2 or 3 boards. I have been working with my t21 zero issues: see below just 2 boards running

Unless it is using 3 separate PSU's with 1 per board, being 3-phase has nothing to do with your problem. If it is just 1 big PSU then 3-phase is just a more efficient way to provide power to the bulk DC power side of the PSU switching circuits. As Phil said, odds are the Bitmain controller is not setup to run with 1 or more hash boards disabled.

he may be able to load braiins onto the controller if it is stock from bitmain. braiins lets you disable boards. As an aside I am playing with a 1 board setting for a t21. I will let it tune and see how it does. I have loki chips which will allow for a totally non stock psu if I use the epic controller. I have a psu that says it will do 1500 watts using 120 volts and put out 13.8 volts with a 15% adjustment pot which means as much as 15.87 volts. I am thinking the max I can do for a board is 60th and pull 1200 watts at 13.8 or 13.9 volts all within the specs of the psu. Thus I am 90-95% sure a 120 volt 1 board t21 miner at 60th  1200 watts is doable. It would be the most powerful 120 volt miner and one of the most efficient.