Swapping Y and E0 on Marlin

Hi,
Not sure if this is the place to raise this question.
I'm testing a reprap based CNC. Hardware is MEGA+RAMPS 1.4 and NEMA17.
Firmware is basically marlin with some modifications.
Obviously I have no use for E0 and E1.
After all worked fine Y axis started to work only on one direction and won't move to the other.
Done some elimination process. swap wiring of X and Y and the Y (connected to the X controller) is working ok - so no problem with wiring.
Swap the drivers - all is the same - so no problem with the controller.
Base on that I concluded that there is some problem in the Y control on the RAMPS board.

So currently I'm thinking that if I can somehow direct the Y commands to go through the E0 it may help me to bypass the problem.
The question is how do I do that?
Tried to changed the PINs numbers swapping the E0 and Y numbers
Nothing really changed

Any suggestion will be welcome,
Dave

When you scroll through the pins.h file,you´ll find many sections.
Each section is dedicated to a certain mainboard.
You have to make your pin changes in the right section to have success.
-Olaf

Thanks Olaf,
It worked but now I'm confused and basically run out of ideas.
Will appreciate any input.
Just describe the situation again.
Machine was working great yesterday and no changes made.
today X and Z work normally Y go only one direction.
Swap the cables between X and Y step motors to eliminate wiring and motors problem - still the same (Y motors work on X commands both directions and X motors go only one direction).
Swap controllers to check if the problem is in the controller. still same problem Y moves only one way.
Change the PINs to check that its not the RAMPS Y slot problem. Now Y is on E0 and problem is still the same.

:-0 What else can it be?

Then it´s a misconfiguration of the endstops.
In Marlin you have to set the homing direction to min ( -1 ) or max ( 1 ) according to the place of the endstops.
Also the endstop-connector has to be plugged in the right port on the Ramps.
-Olaf

Try homing Y first, then it may move normally.

Quote
o_lampe
Then it´s a misconfiguration of the endstops.
In Marlin you have to set the homing direction to min ( -1 ) or max ( 1 ) according to the place of the endstops.
Also the endstop-connector has to be plugged in the right port on the Ramps.
-Olaf

No endstops on this machine and configuration allows to go on the negative
#define min_software_endstops false
#define X_MAX_POS 700
#define X_MIN_POS -700
#define Y_MAX_POS 700
#define Y_MIN_POS -700
#define Z_MAX_POS 300
#define Z_MIN_POS -300

so no homing.
0,0,0 is to where the head is at when the machine is turned on or G92 0,0,0

After all sort of tries I observed that with one jumper less under the controller it moves both direction (not good thought as the calibration is wrong).
My drivers are DRV8825 means all 3 jumpers has to be on.
Another observation which made me even more confused is that if while in motion to one direction it gets a command to go to the other it will move that direction. So it doesn't go that direction from stand still but will go in a continues move.

#define min_software_endstops true // If true, axis won't move to coordinates less than HOME_POS.
#define max_software_endstops true  // If true, axis won't move to coordinates greater than the defined lengths below.

What about these lines?
-Olaf

They are both false