Ok, have an older spindle encoder, the type that is on top of the motor under a little cover, and is basically a toothed gear with a pickup that reads the teeth as they go by..
Now, it originally worked, but not well. At high speeds in the CW direction it would lose counts.. In reverse, it worked great..
Well, I went up there to reset the gap to try to get a bit more sensitivity out of the pickup, and I started it up and it turns about a quarter turn, then shuts off. No tacho signal is present at all now according to the control panel in either direction.
I noticed that there is an adjuster screw that seems to move the pickup sensor back and forth in very small increments. I still get nothing.
I know that the pickup has to have an excitation voltage (similiar to the pickup on a guitar)
I guess I will start there and see. I would suspect that there is a bad connection somewhere between the pickup and the main processor.
My most important question is, anyone know where the connection is made within the panel for the tacho pickup? I am thinking about just rewiring it with high quality shielded multiconductor wire and seeing if that helps. From the pedestrian schemos that are provided with the owners manual, I can't really tell.
Thanks in advance for any help anyone can throw my way!