Let me start with a small disclaimer. I'm not an EDM tech, don't really know all that much about EDM machines, but do have a background in circuit troubleshooting. So bear with me if I don't get all the terminology correct.
I recently inherited support duties for our EDM machines. The audible alarm and stopping mechanism quit working about a week ago on one of the machines. When you jog the ram down and continuity is made between the ram and the base, either by way of electrode touching your material or just shorting the ram and base, the alarm should sound and the ram should retract. The machine is doing neither. Once the ram starts going down in jog mode it doesn't stop on its own.
I've checked the alarm switch, traced the circuitry on the control board back to the power supply cabinet and everything seems ok. There is continuity for both ram and base wires to the power supply cabinet as well. I'd continue to list things I've checked but I could be here all day doing so.
If anyone has any ideas please let me know. At this point I'm willing to try just about anything to keep the remaining portion of my rearend intact. My boss has chewed most of it off already however...
Thanks.