Hard drive on server replaced twice

The hard drive on our application server, Dell Poweredge 2500 (2 years old) failed twice in the last month. The first time, we were also experiencing problems with the tape drive the night before so Dell replaced both the tape and hard drives. Two weeks later, the tape problems were not completely solved (tapes are all brand new and the system still said that the tape drive needed cleaning … which we did). Files were backed up but tape would not eject automatically.
Then, we got a BSOD on the server “Start unit device failed”, “no boot device available”. Question: is it possible that the problems with the hard drives is somehow related to the problems with the tape drive or some other common unit. Because if so, replacing the hard drive will not solve the problem. Note: we also replaced the cable.