X-spot Tilt Fail

Ok,
I have seen this error on several different xspots, and have never been able to nail it down.

What happens is, when powered up, the fixture seems to start to home, but the tilt 3phase board never intitilizes.
The end result is a tilt fail error on the display.
and the tilt motor is never powered up.
you can push the head and there is no resisitance.

As a side problem with this error,
The fixture will still strike the lamp with this problem, and doesn't seem to notice that there are no fans running in the head, as well as that it cannot see the head temp sensors.
This has caused several of my xspots to have melted bezels.

Cycling power always fixes it, but you never know when it will happen again.
Also, homing the fixture does not seem to fix it. the tilt fail error stays.
so if the fixture is hung somewhere in the rig that it cannot be easily powered down, it is stuck for the remainder of the show.

Any help would be greatly appreciated.
Joshua Wood
Related