120T DLT7000-errors on Verify and Restore only

Quick background: Purchased a Dell PowerVault 120T DLT7000 a few months ago from eBay. It worked for a while but the "cleaning tape" indicator started appearing constantly. I replaced the Quantum TH6XF-ES drive with a refurbished drive. The indicator no longer appears, but now I have a new problem which started immediately after replacing the drive.

I’m using Backup Exec 9.1 on Windows 2003 with an Adaptec AHA-3944AUWD SCSI card. I can inventory tapes, catalog tapes, erase tapes, re-label tapes, even back up files-all successfully. However if I submit a job asking for verification or if I simply try to restore a file, I get a job failure notice stating that an I/O error with the device has occurred. The unit itself does not report an error. When a verification starts, the drive will beep three times and make a loud grinding sound as the heads recalibrate. The device displays “Reading� and then after a few minutes, the tape is ejected, but it appears that Backup Exec does not receive the data from the tape read.

I’ve replaced the terminator and both SCSI cables (external plus the one inside the tape unit). I’ve change the SCSI card settings try asynchronous, 10m/s and the default 40m/s settings, all with the same results. I even put the original drive back into the unit and I get the same error message. I’ve used a cleaning tape and I’ve tried several different tapes for the backup job. I've tried both channels on the SCSI card as well. I am able to restore using the original drive connected to an internal channel on the SCSI card, but I get lots of soft read errors (assuming from the bad tape heads).

I’m running the latest firmware on the PC, SCSI card and tape drive. I’m unable to upgrade the firmware for the loader from 114 to 116 because the scsiwm.exe application is unable to find the ADIC FastStore changer (although it appears in the device list and within Backup Exec). Bacup Exec has all updates applied.

I’ve already put a lot of money in getting this unit going again (since it is no longer under warranty) and would even be willing to pay $50 to the first person who places the “winning suggestion.� SERIOUSLY!!!!!

I’m thinking it is the circuit board located directly behind the drive, but I’m afraid to replace it without getting other professional advice. I’ve included the Event Viewer error logs below. Thanks in advance for any help!

Application Log Errors:
---------------------------------------------------------------
Event ID: 33152
Adamm Mover Error: Read Failure!
Error = ERROR_IO_DEVICE
Drive = "QUANTUM 1"
    {8E69C15E-8AD8-4D0D-820E-B6D98387F492}
Media = "Test.B"
    {900BC442-816E-4739-A317-0523C7D7282A}
Read Mode: SingleBlock(0), ScsiPass(0)
Write Mode: SingleBlock(1), ScsiPass(1)
---------------------------------------------------------------
Event ID: 33152
Adamm Mover Error: Read Not Ready Failure!
Error = ERROR_DEVICE_NOT_CONNECTED
Drive = "QUANTUM 1"
    {8E69C15E-8AD8-4D0D-820E-B6D98387F492}
Media = "Test.B"
    {900BC442-816E-4739-A317-0523C7D7282A}
Read Mode: SingleBlock(0), ScsiPass(0)
Write Mode: SingleBlock(1), ScsiPass(1)
---------------------------------------------------------------
Event ID: 57665
Storage device "QUANTUM 1" reported an error on a request to read data from media.

Error reported:
The request could not be performed because of an I/O device error.
.

 For more information, click the following link:
http://eventlookup.veritas.com/eventlookup/EventLookup.jhtml
---------------------------------------------------------------
Event ID: 34113
Backup Exec Alert: Job Failed
(Server: "SERVER") (Job: "2") 2 -- The job failed with the following error: The request could not be performed because of an I/O device error.
 
For more information, click the following link:
http://eventlookup.veritas.com/eventlookup/EventLookup.jhtml
 
 
System Log Errors:
---------------------------------------------------------------
Event ID: 11
The driver detected a controller error on \Device\Scsi\aic78xx1.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
---------------------------------------------------------------
Event ID: 15
The device, \Device\Tape0, is not ready for access yet.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.