Hi guys, ,I have recently bought a Prusa i3 printer but the display is only a blank screen, I have tried adjusting the screw behind the screen but it doesn't help, only changing the coarse factor, can somebody tell me how to fix this and also what exactly is the issue? THe screen is on so definitely it is working but no directions displayed, is it possibly a firmware issue?by Prusrai3 - Prusa i3 and variants