I just purchased another Compaq 35/70 DLT drive. It arrived this weekend with a broken faceplate, but otherwise it looked OK. I spent hours swapping the $(^#%@ thing into triumph and removing the old DLT drive. I also tried to swap faceplates from the old drive to the new drive and found that the ribbon cable connecting the SELECT switch and status LEDs on the right (looking from front) on the old drive was damaged. No wonder I could not eject the tape!. I also ended up destroying the tape that was in the old drive because I could not get it out easily.
Nonetheless, I finally got the newest drive into triumph. Lo and behold, I got the same *&%^& I/O error writing to the drive. Now I was really getting frustrated. Three 35/70 drives cannot all be bad. I swapped tapes and that seemed to resolve the problem -I tarred the /home filesystem with no problems. It is time to try amanda yet again.
UPDATE (06/12/2005, 11:09): After almost two months of amanda backups, this drive seems OK. I conclude that the other two drives (now both at Matt’s house) are bad and that some of my tapes are bad. When I use new tapes in drive #3, all is well.