Originally Posted by
Microtest
Hi all,
Seen plenty of other posts on this, but figured I'd throw my situation out there to make sure I'm not under any false assumptions.
Recently took over my father's little machine shop in southern California. I'm not well versed in machining, so I have a machinist that works the machine for the time being.
A couple weeks ago, he had to hit the emergency stop on the machine as it seemed to skip some programming and tried to go to a different spot on the board.
Ever since, the z axis stepper motor no longer works, but x and Y still work. It sounds like it's trying to move, but it only rotates a tiny bit whenever a step is attempted.
I hooked the motor up to the x-axis control wiring, and the motor worked fine. So it seems to be isolated to the z control...until I had a dumb idea.
Some folks I knew looked at it for me and said they weren't getting power to the z wires, which seemed odd to me. Regardless, I figured I'd see if I could pin down the bad wire by trying to recreate the issue on x-controls by disconnecting a single wire, X5 yellow-white. Tried moving a d to my surprise the motor rotated for the step, then stopped. Tried again...same behavior as the z-axis. Even afterchooking the wires back up to the x-motor, same behavior. So now I only have a working y-axis.
Fuses seem okay, the have continuity and seem around the 0.5k ohm resistance.
Looks like this bridgeport has the SMS board and diodes across the power transistors, so I'm guessing later model of the series 1 to help avoid blown transistors when E-Stop is hit.
I swapped the X and Z SMD boards into the Y slot, and the Y axis worked fine on all of them, so I don't think its the X and Z SMD boards themselves. My only other leads are maybe the ACC board, or power transistors for the X and Z axis.
I actually have a series 1 manual on hand,so I've been digging into that, but would rather get some other info, lest I goof this up more than it already has been.
How best to check my transistors? Where can I get replacements? These are fairly old, so not sure if I should look for originals or identify a valid alternative for these components.
Is there anything else I should be looking for?
Thanks for any info or help. I've called around to various technicians, and it looks like this machine is a wee bit....aged, as there doesn't seem to be anyone who can work on these things.