Just unpacked another Z9 Mini. Overclocked it to 650.. and board 2 has a chip that blows out (00x0) rebooted it and 2 mins in same again....
Just droped the freq to 500 runs fine.. popped it up to 625 and still fine for now..... board 2 is very lazy 3.61
I am reading other sources that report exactly the same as you, and this is putting me off getting another 2 or 3 of these. I think i will go for the Z9 big boy one next.
May i ask on your other mini's do you get any 'Rejected' shares? As a newb to Asic mining, i am used to GPU mining, and avoid these rejected shares, by dropping the offending card(s) a tad in the overclocking specs.
Not sure in ASIC mining if these are the norm as the hash rate is huge compared to GPU's, or should i throttle down a bit?