I remember our AASP being sent one of these back in the day. As I recall Apple expected the dealer to pay for it. Of course. At the time of Service Exchange, Apple were getting back a lot of No Fault Found boards and tacked on a handling charge to the dealer. So this was seen as a way of sanity checking a part swap to avoid such chargebacks.
As I recall, whilst we found it a cool toy, most of us had enough diagnostic skill hours logged that we generally already called the problem. I don't think our dealership decided to keep it.
SCSI HD Tests for Apple SCSI hard disk drives. - CPU Tests Vol 1 - Mac Classic, SE, SE30, II, IIx, IIcx. - CPU Tests Vol 2 - Mac LC, LC II, Classic II. - CPU Tests Vol 3 - MacIIci, IIsi, IIvi, IIvx, and Pf600.