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

Update just blown out again 00x0 at 625
reduced to 600