A customer brought in a seagate 7200.7 today. He reported that it did not show up in BIOS so he found the plans for the seagate terminal adapter online and put one together.

Among other things, he reports that the terminal worked fine until he ran R1 in the 2 level, at which point the drive no longer responded to commands. When I view the drive in terminal it shows the initial information up to SATA reset and then is nonresponsive and the drive clicks and eventually spins down. The customer says it did not do this previously.
From my available reference it looks like R1 in level 2 should have merely output sector 2 of the current track, so I don't see why that would have caused any issues. The customer says he read online to do R1, R2, and R4, so I guess he was reading a reference of F level commands.
Anyone have any thoughts? I'm assuming he must have done something else while he was messing with it that caused some issues. I've never seen a drive that never at least came up to an F prompt or streamed out errors or something.