Help with scsi tape drive problem

I've had a scsi hard drive, scsi tape drive, and cd rom working off an adaptec 29160 controller. Everything worked great until a few days ago. I begin getting tar format errors (running sco 5.0.6) on the tape drive and occasionally the entire system would hang up while trying to access data on the tape. I replaced the tape drive but I'm experiencing the same problems with the new drive. I tried another identical controller card and that didn't solve the problem either. I don't know what to try next. Any suggestions? Is it possible the scsi cable has gone bad?

---------- Post updated at 03:07 PM ---------- Previous update was at 12:38 PM ----------

Apparently the cable had gone bad. I replaced it and the problem went away.