Navall 2 android update help needed

[lasercutter]

Hi all, probably a long shot but I recently recovered my old Navall 2 headset from my sister and was planning on selling it, however the notification bar refuses to work so thought I'd try updating it from android 4.2 to 4.4
Problem is finding the files, so I was hoping someone here might have them or know where to get them, really don't want to sell a faulty unit if it's possible to fix it.


Many thanks