Stepper Motion

Stepper motor, wire, stepper driver, RAMPS board, or Arduino itself can be broken. How to identify which it is? Here is a systematic procedure that verifies things from easiest to hardest.

Replug, replace cable - quick
Replace stepper driver - quick
Replace stepper motor - 3 screws, 1 belt plug, and we're done! By design, the 3 mounting screws are exposed - motor can be replaced in situ without any other machine disassembly. Entire procedure is done in 5-10 minutes including retest of correct motion direction. MJ data point was 10 minutes.
Replacing RAMPS - a number of connections must be disconnected - about 20 connections must be disconnected Takes 5-15 minutes
Replacing Arduino - zip ties must be cut, board must be separated from the RAMPS, most connections must be taken off. This is about 15 minutes for a skilled person. A clear video is needed here to train someone fully on this procedure.

Axis Repair

For axis replacement - if kept at the correct length, the top snaps in first, then the bottom.
To replace the Z motor -
- Remove bed rod holder
- snap off the bottom of axis first.
- Remove belt peg.
- Loosen 3 motor screws (3mm x 25mm)
- Replace motor. Make sure that the belt slips over the motor pulley, not underneath it.