Running a STX 435 with hyd steering valves & Trimble 500. Last night we moved to another field and after setting the AB line the 500 wouldn't engage on the AB line. I tried resetting the AB line, rebooted several times and it still wouldn't engage.  The AB line shows on the screen & it wwill "paint" but won't engage, I just get a beeping.  The "steering wheel " icon on the left side of the screen isn't showing. When I quit later I noticed the alarm bzzer was beeping even after I shut the 500 down. It wouldn't go off until I shut the tractor off.  I did a littile searching this morning & when I checked the soft ware firmware version it read "0000000000". I'm not that knowledgeable but shouldn't there be a firmware version #? Has my 500 taken a dump?

T.I.A.

boog