R2E3 X-Axis problem

[Jadaan27]

Hello. I'm having a problem with my R2E3. It has the BOSS 8 control. I turn on the machine and it powers up fine, no errors. I enable the drives and they turn on. But my X-axis will VERY slowly move or drift by itself. Now when I go to home the machine the Z-axis homes first no problem, but then the X-axis will rapid about 1-inch towards its home position and then the drives will kick out and I get an "axis limit" error.
Every time I enable the drives my X-axis will drift really slow by itself. I can move it in JOG mode in both directions before executing the machine HOME. But whether I press the + or - direction it will rapid fast in that direction about 1" and then the drives kick out and I will get the "axis limit" error.
The machine had its initial problem in the middle of running a program. The x-axis did a programed rapid move and then the drives kicked out, spindle turned off, and I had an "axis limit" error. Now I've had this x-axis drift problem ever since.
I cleaned the connectors on the NC400 boards. I tried swapping the controllers but that didn't make a difference.
I've had this machine for 3 years now and this is probably the first problem I've had with it.
Anyone have any suggestions?

[machintek]

If an axis drifts when powered it has an open position loop. This could be the encoder, or cable, or a board.
Swap the motor with the Y axis and see if the problem follows the motor.

George