@greekredeye you can check the lead screw/anti backlash nuts pretty easily. Possible those nuts bound up and locked it, or you could have an issue with the rails and slides. You can find out if either is the issue in about 15 minutes with the steps here:
I go into a lot of checks in there, but you can skip that and get to the part where I disassemble it. The main thing to watch is not dropping the rail slides off the end, it will make you sad when the bearings go flying everywhere. 
And really, you can check the leadscrew nuts even faster by putting a box under your router mount to support it, the remove the 4 motor screws and the 2 lead nut screws. (There’s no support in this photo, but the arrows are pointing to the screws to remove)
Disconnect the power connection to your motor and you can pull the leadscrew and nuts out through the top. Now you can check the nuts, see if they are bound. Then check the carriage, move it up and down on the rails. (Do not let it come off the bottom, keep something underneath to support it!) If those are all good, then it could be the stepper motor.