The Omega temperature controller for the BCM cavities read "open". I burnished the Copper male connector on the back with a file, plugged it back in, and the temperature is now ramping. The Constantan looked fine. I have little confidence that I couldn't have achieved the same effect by prayer, bad language, or jumping up and down on my heels.
Temperature regulation has been goofy since the BCM cavities moved downstream, but that may just be a confusing coincidence. It's true the thermocouple wires got all scraped up, but they can't all be intermittent in the same manner, can they? Since the move, I believe the solid state relay (or equivalent) has been replaced, then Joe replaced the temperature control module, switched from one wire to another, reterminated the leads, etc. We've been missing the root cause, something common to the system even after all these changes. Like a handful of 10 year old, tarnished Copper connectors? I'll check on the regulation tomorrow. There may be another in-line connector downstairs that needs some love.
A copy of this log entry has been emailed to: musson@jlab.org,hornt@jlab.org, beaufait@jlab.org