I just built a cnc router and I'm having some problems that I just cant figure out. I bought a package off eBay from China (www.longs-motor.com) for all the electronics, it was a 4 axis setup, Nema 34 motors, DM860A drivers, and a breakout board. Using a old emachine cpu, XP, 1ghz ram, on mother board printer port.
So here is the problem. Last night I hooked everything up and went through the setup process and had it cutting circles and getting ready to set the backlash comp up, and decided to wait till today to finish. Went out this morning and started the machine up..... got Z axis, got X axis, no Y.... what the heck... so I checked the ports and pins setting, then switched drivers to a spare one, got movement in the -Y direction when jogging -Y and +Y. So then I thought maybe the BOB, wires, or port is bad. Pulled out the trusty Multimeter and went to checking pins. Everything from the computer, cable, to the BOB looked fine..... The BOB must be bad and fried the driver..... I better stop before I fry my spare driver..... So I ordered two breakout boards (1 spare) and another spare driver....  Went to movies and messed around but still was baffled how one day it worked and the next it didn't (this is new stuff).. So I did some more checking. Took the Y axis motor and hooked it to the X driver and the motor worked fine. "Good the motors not bad"   So then I hooked the X axis Puls and Dir wires to the Y driver that only moved one way (spare driver)..... Still only moves one way "Bad driver"    OK Lets hook the original Y axis step driver to the X axis Motor and Puls and dir and power... Nothing .........  a few choice wards about china and so on 
So this is my question, whats the chances of getting one bad step driver (the one that moved only one direction), and a Breakout board going bad frying a step driver ( original step driver). Or is there something I'm missing here... 

I know it's no help to you but you would not be the first to get bad stuff from China.

When setting everything up you must ensure that the driver's motor current settings do not exceed the motor's rated current otherwise you will fry the driver or perhaps damage the motor - the stuff from China rarely has any tolerance for errors. Having said that I have been using a Chinese driver board for some years now without any problems (perhaps luck is involved here).
Also - perhaps a better quality BOB may be a good investment.

Tweakie.

Thanks Tweakie
This is something that has me scratching my head. I had the drivers set at the lowest current setting (2.8A Peak/2.0A Rms). Your right about the BOB I was planning on replacing it from the start. Did some testing on the bob and it didnt go bad. I just recived two bad drivers, whats the luck of that.

Pretty bad luck, I would have to say    but perhaps that's the way luck goes sometimes.

Tweakie.

just checked out your website... sweet laser I just ordered a laser. any must have software, any words of wisdom

It depends if you are to use GCode to drive the laser - the laser thread has most of the details (you will have to skip through the boring parts because the thread has got a bit long now). http://www.machsupport.com/forum/index.php/topic,12444.0.html

If it is a laser machine (which use a form of HPGL) this forum may be of interest to you http://oplaser.co.uk/opsupport/

I would be most interested to hear how you get on with the laser.

Tweakie.