Try some other commands. There is a (partial) list of commands here: http://files.hddguru.com/download/Datasheets/Seagate/Seagate%20Diagnostic%20RS-232%20Port/ Are you doing this with: all contacts connected head contacs insulated motor contacts insulated (please choose one) jaclaz Head contants insulated with a piece of folded over notebook paper. I found that if i did ctl-z and then /2 with 1 second of drive power on i get the F3 2> prompt However if i issued the Z command immediately then, it gave the error LED:000000CE FAddr:00280569 If however i waited a short duration before issuing Z, it stopped responding at all not even echoing Z ____ EDIT ‒‒‒‒ Tried it with the board completely removed from the drive until after Z, and it worked fine to that point. reattached board carefully and securely, as expected the drive was not spinning issued U to spin up the drive, and it started spinning, but seems to never finish the spinup, and accepted no more commands