RAMPS "Y" motor problem

I just got my RAMPS 1.4 board to comunicate w/ the computer (using the curent version of Marlin and pronterface) and there seems to be a problem with the "Y" motor controls. When I attempt to move the motor it stutters, stops does some weird vibrating and then refuses to move. I thought that it may be a mechanical problem w/ the bearings but when I hooked up a free standing stepper motor it did the same thing.

Could it be the Pololu chip?

I am not sure where to start on this one and I do not want to perchance another board if I do not have to.

Have you adjusted the trimpot on the Pololu? Too little or too much voltage can cause the stuttering you're seeing. Also having the motor wired wrong can do that, or having the plug in wrong.

I know where to take the reading but what number am I looking for? I am reading 1.015 now

Should it be taken when the power is on?

Have you tried testing with the Pololu from another axis in your Y position so that you can rule in/out the Pololu as the cause of the problem? If you have & it still failed then try commenting out/disabling the MAX ENDSTOPS setting in the Marlin config & test again.
MAX Endstop settings caused me a headache recently, & my symptoms were similar to yours. I think there will be a DOS windows running behind Pronterface (if you are using Wondows), & this is useful for spotting unwarranted "endstop hit" messages.

hi
did u fix it?
pleas tel me how
sivan