having trouble with z motors running at same time

[spart]

hi all iam sitting here scratching my head can't figure this out.

i am having trouble running my z axe down to home when i hit the home button it sounds like a lock up when i have both motors plugged in at same time making a hell of a noise and not moving , it dose work fine if i plug in one motor at a time and both motors check out to going to home but not together. it works fine with both motors when in reg use, up and down just wont home

any one no a fix smile. thanks

[spart]

found problem, stepper motor collor hitting, a dunnnnnnnnnn moment back to printing