Originally Posted by
RickPflimlin
My 770 had been perfect for about 1,000 engraving programs, when it started making a grinding sound last week. It then lost steps on the X and engraved in the same spot ruining the part ($65.00).
Anyway I thought it must be a bad motor or something in the drive system because of the grinding sound. I removed the X motor and everything moved as smooth as butter when turned by hand.
I then started running the motor in and out with the arrow keys on the keyboard, soon enough it started to studder and grind. I thought it must be the motor and went to the computer to order a new one, before I hit send I thought I should wiggle some wires. Sure enough I had a short somewhere. It turned out that the green plug from the motor wires to the microstep drive (little black box) was never tight. I pushed it in and there was a loud click and my problem went away.