Netbackup restore issues with HP LTO5 tape library

[Rockey_Wen]

Is there anyone have experiences on restore LTO3 tapes in LTO5 library using Netbackup 6.5?

The issue is that when we attempt to restore data from an LTO3 tape in the MSL4048 LTO5 drive the robot drive returns a communication error, the drive also disappears from the Windows device manager on our media server aupbackup03.
The MSL4048 returns the following error.
 
10.08.17 15:45:19.87  Libctrl task Error - HE: drive communication error
     Return status:                   0x80 - command failed
     Global error code:               0xF1 - HE: drive communication error
     Module error code:               0x01, 1
     Current command:                 0x17 - physical move
     Task originator:                 0x0F - Remote management interface
     Extender library specifier:      0x00 - master library
     Sub error type:                  0x01 - native SDCI error
     Data:                            Sdci return code 20, Error code 01,
USART error code 00, number retries 00
     Source element type.:            0x04 - tape drive
     Element number:                  0x01, 1
     Destination element type.:       0x02 - storage slot
     Element number:                  0x05, 5
     Component ID type:               0x02 - medium PVT (barcode)
     Component ID:                    TF0407L3
 
Before we attempt to restore we change one of the MSL4048 drives in Netbackup from HCART2 to HCART3, this is also what the Symantec support rep advised to do.
We then initiate the restore, Netbackup detects that the tape is in the library and mounts the tape into the drive that has been configured as HCART3.
I can see from the HP MSL4048 console that the tape has been successfully mounted into the drive, but when Netbackup is in the process of locating the position on the tape the communication error occurs on the robot

[Marianne · Accepted solution]

The fact that the drive dissapears from Device Manager and this error from the library:
0xF1 - HE: drive communication error
points to a hardware error.
Start with logging a call with the hardware vendor.

This extract from a status 84 TN must always be kept in mind (the same applies to read operations):

As an application, NetBackup has no direct access to a device, instead relying on the operating
system (OS) to handle any communication with the device. This means that during a write operation NetBackup asks the OS to write to the device and report back the success or failure of that operation. If there is a failure, NetBackup will merely report that a failure occurred, and any troubleshooting should start at the OS level. If the OS is unable to perform the write, there are three likely causes; OS configuration, a problem on the SCSI path, or a problem with the device.

[Rockey_Wen]

Thank you very much for your help, Marianne.
You're really genius.