Our '94 Mori SL-25 w/Fanuc 16T dropped the X-axis to the lower hard limit when the operator stepped away for lunch the other day.

No alarm other than OVERTRAVEL was indicated.

When the OVERTRAVEL RELEASE button is held in, we can rotate the manual pulse generator and the position display counts up as if the axis is moving but there is no actual axis movement.

Initially I thought that the motor-to-ballscrew coupling had loosened up but when I checked it there was no motor rotation when I was watching as someone rotated the MPG.

The Z-axis has the same behavior. (i.e. the position display counts up but no actual movement.)

The servo amp is A06b-6066-H244 and controls both axes.

Any ideas? Faulty servo amp? Faulty axis card? Other?

Any help will be appreciated.

emexcee380