Nema 23 Twitch

I'm running a set of RAMPS 1.4 off of an ATX power supply. It's driving a Rapman 3.1, what's left of it at least. I'm trying to get the RAMPS to interface where the old electronics did, with the exact same configuration.

And having absolutely no luck. I'm working on homing right now, and I've been able to get the X and Y to home nice and smooth and quiet. Then it's Z's turn and it just twitches, growls, and stubbornly remains still. I've tried switching everything around in Config, tried all the different pin combos (and returned to default, all three motors are identical), and still no luck.

Any words of wisdom from the masters?

EDIT: It was the trimpots on the driver. Thanks for all the help! I found my answer on a different post.

Edited 1 time(s). Last edit at 04/04/2013 10:38PM by Morpheus.

When you say twiching and staying still it reminds me of when I wired my motors wrong.

Take a multimeter and test the resisance of the two side pairs (left two and right two) of your z-motor. They should have some resistance(and be similar) where going to other pins should be open.

If you find that ones other than left and right have some resistance(are connected) by trying different combinations, rewire the connector to have left and right sides be connected.

Hope this helps!