Z axis issues

I am currently having issues with my z-axis. I am unable to perform both a G28Z command and a G0Zxxx command. My steppers (two steppers for z with 8mm acme screws) just buzz briefly then stop.
It sounds like there is not enough current to drive them.
However, I am able to move the axis both up and down using the manual controls inside of a program such as pronterface or repetier.

This is a brand new build and I'm using an autoleveling probe. I'm not sure if any of that would be making this issue.

It is possible you have the feedrates and/or accelerations set too high. You might want to back them off (maybe to 1/2) just to see if that is the issue.

Having the exact same issue using Repetier-Host. They work normally in pronterface.

Thanks for the help. It looks like I had my DEFAULT_MAX_FEEDRATE too low.

Too Low? That is a new one! Usually the problem is people crank them way up because they want things to be faster.