Machine crashes hard on xorg exit

[Gregory Orange]

Hi everyone,

I've got X working on a newly installed machine, right up to the point
where I quit X to go back to the console. The machine then crashes
hard, with a blank screen, ssh connections all freeze, no response
other than holding in the power button, and no log entries I can find
after booting up again.

I'm looking for some advice on how to troubleshoot this. Here are some details:

Intel NUC, Core i3
FreeBSD 10.1
xorg-7.7_1
X running with no xorg.conf so I guess autoconfigured

TIA,
Greg.