Motors not moving, everything seems OK...

Hi,

I wired my RAMPS 1.4 this morning and there is something amiss. But I cannot figure it out. What I have:
- RAMPS 1.4
- Marlin firmware downloaded only last week, CoreXY defined, steps per unit defined, all nice.
- A4988 drivers, set at 0,6V.
- Pronterface on the PC to try to get the machine to move.
- I checked on the A4988s, VMOT is 24V, GND is indeed the negative connector of the power source, VDD and Enable are both 5V.
- No end switches hooked up yet.

All fires up nicely, the LCD on the printer reads '3D printer ready', no errors. Via Pronterface, I can heat the hotend (I burned my finger...) and I get proper feedback of the temperature. I can also ask Pronterface to move in the X, Y an Z directions. On the LCD screen, I am told they moved the requested distance. But the motors didn't move, nothing happened. So the system thinks all is OK and it performed, while actually nothing happened.

What can I check? I could see something fail, but all drivers / motors at once I don't believe. I don't hear any humming of the motors when stationary, I did hear that on the NEMA 34s I had on my CNC router long ago. It seems the drivers just don't get signals to move.

Cheers,

Hugo

Edited 1 time(s). Last edit at 08/12/2017 11:40AM by HugoW.

Just tried; the motors are not energized. Their turn just as easy by hand with the system powered up, as when the system switched off. BTW, I don't have the end switches plugged in yet.

Hugo

Edited 2 time(s). Last edit at 08/12/2017 03:08PM by HugoW.

RAMPS 1.4 Assembly Guide

[www.reprap.org]

Insert jumpers to RAMPS 1.4 --------------------------------------------------- 4

Thanks, but they are all in there.

Hugo

It was worth a try! lots have forgot them.

Have you considered the stepper motor cable wiring.
I had a stepper cable that each pair was wired A+ to B+ and B- to A-, and I changed wire Pairs to A+ to A- and B+ to B-.

Cable makers do make mistakes.

Edited 1 time(s). Last edit at 08/12/2017 04:04PM by Roberts_Clif.

Quote
HugoW
I don't have the end switches plugged in yet.
Hugo

Might that be part of the problem? Try M119 to see what Marlin thinks about your endstop status...

Finally issue found, one bad driver. I replaced it with a similar one and now it all works.

Cheers,

Hugo