Solved Motors not moving into negative

Recently hired as a Uni Technical Officer. There are 4 R1+ printers that I trying to troubleshoot problems with.
On one printer, using the display or Matter control on a connected laptop, the z-axis didn't allow movement into the negative. Now the x-axis won't move into the negative.
Had anyone else has this problem and solved it?
I have checked connections, and am currently testing with a multimeter, but does anyone have advice on this?

Thanks in advance.
Jon.

 

I'm not so sure about your x-axis, but the z-axis might be an easy fix. I've had the same problem when accidentally moving a z-motor while powered off.
With the power off, spin the motor shafts as evenly as possible until the nozzle touches the build plate. It's best to slide the carriage to the center and drop the gantry a little bit on each side until nearing the plate.
When the nozzle reaches the build plate, move the carriage to one side and adjust the z-motor until you hear the click of the limit switch. My practice is to lower the carriage until the switch closes (one click) then barely raise it for the click that represents an open switch.
Repeat this for the other side, then return to check the first switch.
For your x-axis problem, you may have a switch involved, but I don't have easy access to my machine to make suggestions.

 

Thank you for this fix fred3d. It worked for the z-axis and the x-axis seems to be behaving.