Do you have the SCSI module installed? If so, I think you have to install the Prommy in the bottom slot, obstructing all other Zorro slots. There is a way around it though, use the prommy with right angle PCI adapters. I posted guides here a few years back on how to use a Prommy in a desktop A3000 and A4000, but the concept would work in a A4000T also. That should free up some Zorro slots.