initial test: motors not responding

Greetings,

I am currently working on a prusa i3 re work according to the following instructions: [www.instructables.com]. I got up through step 10 when I found out I could not manually move any of the axis. I am in the process of trouble shooting the ramps 1.4 board. I downloaded the the ramps 1.4 testcode.pde from the following wiki page: [reprap.org]. I have one motor hooked up as seen in the attachment, but it doesn't seem to be receiving any signals. My question is, should I expect a response from the motor when running the ramps1.4 testcode? Is there a safety on the board which may need to be bypassed with my current set up? Please help me understand.

Thank you,

Reggi

The steppers should run back and forth and some LEDs should light occasionally.
Do you have a 12V PSU connected to the green connector?
Are the stepper driver boards placed correctly ?( pictures where the potmeter shows the orientation can be misleading *askmehowIknow* )
-Olaf
PS: Where is the attachment you mentioned?

Have you checked the motor wiring pairs?
Have you tried adjusting the stepper pots?
Are there 3 jumpers under each stepper?

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My updated Instructable on our Prusa i3 Build
[www.instructables.com]

Sorry about that, I have updated my original post with an attachment of my setup. I've tested my motor pairs. I have 12 volts connected to the ramps board. I tried tweaking the stepper pots and I have 3 jumpers under each stepper. I also tried using DVR8825 stepstick vs the A4988 driver and I still have no response. Is there a more basic test, other than the ramps 1.4 testcode, that I can carry out to test my ramps 1.4 board/ arduino/ stepper drivers?

You have to find the wire pairs that build a coil.
Therefor unplug the stepper from the Ramps board and shortcut two wires of the stepper. Turn the shaft by hand. Do you feel a higher resistance? Bingo, you've found one coil of two.
Now do the test with the other two wires to confirm they are OK,

The wires of a coil should sit next to each other on the connector. ( That's what I believe is wrong with yours )
Now the stepper will run or at least hum/vibrate.
If it doesn't run, switch the wires of one coil on the connector, now both coils run the same way.
-Olaf

I wish that was the issue but it seems to be hidden deeper than that. I have attached two photos showing my pairs are configured in a way you suggested. I have resistance across the pairs on all 5 motors as well as a voltage spike when I spin each motor manually. Have any other ideas where the problem may be steaming from??? Like I said, I have zero response from all the motors running the ramps 1.4 testcode and I have 12 volts attached to my ramps. I also measured a Vref of my stepper drivers and for the 4 of them, the range was from 1.0 V to 1.22 Volts. Any other other suggestions??? I

-Reggi

There are pins on the drivers called "Vmot" and "GND". Do you see 12V there, too?
Does the controller work without USB connected? If not, maybe the 5A fuse is broken.
-Olaf

Thanks Olaf! You were right. The problem was in the 5A fuse. I thought it was bad at first but looking closer, I found out both the leads were covered by the yellow coating. All I had to do was remove the fuse, strip the leads, and solder it back in. I now have full control over the motors. My stepper motors give out a pretty high pitched hum when in idle. Is that normal?

-Reggi

*UFF*
Good to hear you've found the reason...
Your Vref of 1-1.2V seemed pretty high, that's probably the reason for the whining steppers. See, if you can live with 0.4-0.6V without skipping steps.
-Olaf

Edited 1 time(s). Last edit at 01/05/2016 03:58AM by o_lampe.