X Axis no torque in one direction

[tigger]

I have an issue that is extremely frustrating.
The X axis works fine moving away from home, but it will start skipping steps (a lot of steps) in the home direction.
The motor works find under no load. Plenty of torque away from home, as soon as you even touch the motor spindle in the home direction, the motor starts to skip.
I have:
Swapped the motor with a different motor.
Replaced the motor
Replaced the bearing.
Adjusted the voltage on the motor driver.

Any thoughts what this could be?

This printer has been nothing but trouble. Had it for months and only managed to get one print out of it.

Thanks.

[William]

Hi,some tips for you:
1.Measure if the driver voltage is enough with a multimeter.
2.Swap the driver on X axis with other axis.
3.Change another motor wiring for X motor.

[tigger]

Thanks William. I've changed the cable, too, and swapped motors around.
Which posts do I check for voltage? I have the Prusia i3 aluminium. I'm assuming they wires are coloured correctly (Red positive, Black negitive).
Thanks

[William]

This one:
http://www.geeetech.com/forum/viewtopic ... 17&t=17038

[tigger]

Thanks. I'll give that a go.

[tigger]

Ok, I tested all, just in case. Z and y axis read just over 0.8v, and 5 volt on the driver directly.
X axis reads 5v on the board, but 0 on the potentiometer. Turn the potentiometer clockwise. Still zero.
Dead driver?

[William]

Yep,maybe a dead one.
According to what you said,i guess you didn't remove the driver A4988 of Y/Z and plug it to the X socket on the board?
I think you can have a try to confirm it?

[tigger]

Great suggestion. I swapped the x and y driver board around. The y axis board in the x axis position shows 0.82v on the potentiometer.
The x axis board in the y axis position shows 0v on the potentiometer.
Definately looks like a dead driver board.
I've just ordered a new one. Thanks very much for your help!

[tigger]

I did. Any other driver board in the x axis socket works fine. The x axis board in any other socket, does not.

[William]

I think we can say it's a bad one now...