RAMPS 1.4/Mega 2560 Pololu drivers ok but X,Y,Z rotate only in one direction

Hi everyone,
I bought The RAMPS 1.4/MEGA 2560 pre-assembled and wired motors from Ultimachine.
Running Pronterface with Marlin firmware, I get the extruder going back and forth as it should, but the X, Y, Z move in only one direction!!!! Motors are not connected to any load yet.
Switched the drivers with the extruder driver and same thing. So, it's not the Pololu drivers.
Any ideas? I am losing my scalp from scratching my head

Are the endstops connected?

If not disable in firmware for testing...

No the end stops are not connected.
Why would it matter? the switches are wired as N.O. (Normally open).
After loading the Gcode file, it happily starts printing, but only the extruder motor rotates both ways.
Thanks.

//// Endstop Settings
#define ENDSTOPPULLUPS // Comment this out (using // at the start of the line) to disable the endstop pullup resistors
// The pullups are needed if you directly connect a mechanical endswitch between the signal and ground pins.
//If your axes are only moving in one direction, make sure the endstops are connected properly.
//If your axes move in one direction ONLY when the endstops are triggered, set [XYZ]_ENDSTOP_INVERT to true here:
const bool X_ENDSTOP_INVERT = false;
const bool Y_ENDSTOP_INVERT = false;
const bool Z_ENDSTOP_INVERT = false;

This is what I use, with NC switches wired in, so put a jumper on the ramps endstop pins if you don't have actual switches mounted on the machine. If it is not jumped, the motor should still be able to run in one direction only.

by Kabory

Edited 1 time(s). Last edit at 12/05/2011 06:32AM by pikelo.

Thanks guys.
I had it wired as normally open, where it should've been normally closed.
Problem solved
Many thanks.