MAX Optical tester does not recognise the USB memory drive.

Applies to

MAX-700B/C/D series, MAX-FIP, MAX-900 series, MAX-5205


If your MAX optical tester is not recognizing an inserted USB memory drive in File Manager or Data Mover, please follow the trouble-shooting steps that follow.

Troubleshooting steps

Possible Cause 1: The USB memory drive has not been detected.

Proposed Solution:

  • Disconnect the memory drive, and connect it again.


Possible Cause 2: The file system used on the memory drive may not be supported.

Proposed Solution: 

  • The supported file systems are: FAT, FAT32 and exFAT. The NTFS file system is not supported.
  • On a computer connect the USB memory drive, and then back up any important data that you want to keep.
  • Format the USB memory drive to one of the supported file systems (FAT, FAT32, or exFAT).


Possible Cause 3: USB memory drive no longer seems to be detected after browsing the maintenance and recovery menu.

Proposed Solution: 

  • The maintenance mode of the MaxTester has been enable by mistake. Restart your unit.


Possible Cause 4: USB Icon no longer created.

Proposed Solution:

  • Under normal operation the unit will increment the USB memory drive icon number when more than one USB memory is plugged in to the tester.
  • File Manager view:

    File Manager Directory view

  • Data Mover application view:

     Data Mover application view

  • If the USB key is quickly removed, swapped and re-plugged while being in the file manager, it will re-enumerate the Removable Disk with a different number.
  • It appears as if a ghost is kept of the USB key files and folders, but they are empty.
  • A refresh doesn't fix this and after a few attempts, when reaching RemovableDisk9 it no longer creates a new icon.
  • A reboot (power cycle) should resolve the issue.


Possible Cause 5: There is a system configuration issue.

Proposed Solution:


Possible Cause 6: The USB Memory drive is Bitlocker encrypted.

Proposed Solution:

  • When connecting the flash drive to a PC, a prompt requests drive encryption. If refused, drive becomes "Read Only" and you cannot copy or paste files. If you accept, a password is requested to unlock, which is NOT supported in Win Ce 7 (MAX tester OS).
  • Solution is to use an unencrypted USB memory drive.


Possible Cause 7: There is a Hardware fault with USB port.

Proposed Solution:

  • Please request an RMA for repair at an EXFO authorized service center.