Just noted that my navigation is not working even though everything else seems fine.  Nav gives me a blank screen. 

Updated the firmware to today's latest (v.1.21)  This does not help, Same problem

Can't change clock for DST.  Ideas??  Must have happened since the last time change.

downgrade firmware 1.14
in the Debug menu, you can set the time manually

maybe a short on the screen cable. clue (check back light cable power)