Just exactly what do you mean by "trying to move the spindle"???
If the spindle is activated by an M03 or M04 without an RPM specified by an S word, the spindle will sit there and when you try and physically move it the load meter will register. This is potentially DANGEROUS.
If not under power, the spindle should rotate freely.
So, are we talking about a technical electrical problem or a programming/operation issue? What do you mean by "repair"?