Desperate...Help...HP 9-track drive...

Hi all, Frustration! I just got around to trying to install the OS tapes for my HP3K...and the drive doesn't want to load anymore. I had originally tested it after assembling the HP-IB interface boards with a blank tape, and it loaded and found BOT just fine. Now that I finally get the OS tapes, it's stopped working... It's an HP 7974 with the hp-ib interface. I string the tape and push load, the tension arms engage, it spins, then the lcd reads "*F5" (or "*FS" - it's an lcd...) and eventually returns to "OK". But of course the tape's not loaded, and I have to manually push reset to get it to attempt loading again. Anyone have any ideas? The Big Question: Does anyone have any docs/printsets for this machine? I'd like to know more about the self-diagnostic functions and dip switch settings on the controller board.