Question : Problem: LTO-1 Tape Drive will not read new tapes. Used tapes are fine.

Have you ever heard of a scenario where a tape drive will have no problem with used tapes, but will not
read/write new tapes?

I purchased 10 new Fuji LTO-1 100/200 tapes for my Dell Powervault 110t LTO-1 drive.
I tried using the tapes and my job would fail.  I tried several of the tapes with the same
result.  I contacted Dell.  I downloaded and tran diagnostics.  I tested at least 5 of the tapes
and they all failed.  I tested a tape I had used before and it passed the test.  The conclusion
was the tapes were bad.  I returned the tapes to where I bought them and got 10 Maxell
LTO-1 tapes instead.  The same problem again, the new tapes did not work. Could not
get them to quick erase.  Contacted Dell again.  All ten tapes failed diagnostics.  Used tapes
passed with no erros. Dells conclusion again, bad tapes.   I bought two new tapes from a
local store and those tapes failed diagnostics. My supplier had me send the tapes
to a testing company they use.  The company reported the tapes were fine and to check my drive.
Back to Dell again.  There line the drive is fine, if the old tapes work and it passes diagnostics.
I plan to buy a couple of more new tapes from another vendor to test.  

Any ideas on how to determine with once and for all if it is the drive or the media?
I could understand some bad tapes, but 22 bad ones?

Answer : Problem: LTO-1 Tape Drive will not read new tapes. Used tapes are fine.

It's not the new tapes.

This is conjecture, but what I suspect is happening here is that the servo positioning detection isn't working properly. Even 'blank' LTO tape contains servo tracks for the head to position itself by; if the drive's servo detection isn't working, this wouldn't matter on tapes that have already been written to as the head can still position itself by data already written to tape; but on a pristine tape, there's only the servo tracks to go by, so it wouldn't know where to locate the head and thus stop.

Did you get a SCSI error code? If you did, we can look it up and determine what the drive thinks is the problem.