Follow the steps below to check the firmware version.
Start Remote Setup.
(Windows XP, Windows Vista®, and Windows® 7)
Click Start, (All) Programs, Brother, [model name], Remote Setup.
(Windows 8 or later)
Click Brother Utilities, and then click the drop-down list and choose your model name (if not already selected). Click Tools in the left navigation bar, and then click Remote Setup.
(Macintosh)
Double-click the Remote Setup icon located in Macintosh HD/Applications/Brother or Macintosh HD/Library/Printers/Brother/Utilities.
Choose Machine Info in the folder tree and check the firmware version.
The letter next to Main ROM Version represents the firmware version.