Drives are getting down with the replaced tape library

Hi ,

Often we had issue with right and left magazines of our library and vendor has replaced the entire unit now. After replacement vendor says hardware looks ok. We configured robot and the tape drive. Able to run inventory but when backups are initiated, they stay in mounting state and fail with 252. Drive goes down.

Please suggest a way to get the backups written.

Hardware: Tape Autoloader – Dell Power Vault 124 T