Hello all,

I just built a RepRap Prusa i3 Rework. Heated bed and extruder is heated very well, but my stepper motors don't work.

I connected stepper drivers that screw is the opposite side of the 12V input.

How can I understand that MOSFETs and stepper drivers on the RAMPS fried or not?

Stepper motor links:

How to wire a stepper motor: [www.automationtechnologiesinc.com]
Use a LED to identify wire pairs, (3 links): [www.youtube.com] [www.youtube.com] And [forums.reprap.org]
Tips for beginners: Stepper Motors, bipolar series gets up to speed faster than parallel [www.youtube.com]
Determining what wires to pair up on a stepper motor. Match coils for 8 wire stepper. [reprap.org]

Calibration of stepper motors [www.youtube.com]
How to measure Stepper Motor Voltage [forums.reprap.org]
Tuning and Speeds – Adjusting the Machine's Axes for Maximum Speed, (Kit Supplier) [solsylva.com]

Common Questions and Answers About Step Motors [web.archive.org]
Characteristics of a stepper motor/driver [www.euclidres.com]
Engineering Reference Guide (Stepper Motors, etc.) [web.archive.org]
Control of Stepping Motors A Tutorial. THE UNIVERSITY OF IOWA Department of Computer Science [homepage.cs.uiowa.edu]

Size the step motor with a 100% torque safety factor [www.automationdirect.com]
Motors that run near their rated torque will not last as long as those that do not. Motors should be chosen so that they will run at 40-60% of their torque rating. [web.archive.org]
High torque stepper motors need to run at higher voltages in order for the motor to reach its full potential. Increasing the voltage supplied to a motor increases the rate at which current rises in the windings of the motor. [web.archive.org]
Selecting a Stepping Motor [web.archive.org]
Stepper motor and driver selection [web.archive.org]

Today, I ejeceted stteper pin and measured the voltage on pins (which are 1A, 1B, 2A, 2B ) on oscilloscope. I saw 12 Voltsn DC at each of them. Is my Driver dead? or what is the problem?

Edited 2 time(s). Last edit at 07/17/2014 08:59AM by bhoke.