First, a clarification.  The shift crew was getting messages like this: "epd_controller fc_sensor.C:#487 EPD: TUFF[2]: voltages still bad -- check TUFF if RUNNING"  After some discussion with Tonko, we realize that this occurs whenever the LV to the TUFF branches is zero, which happens when the state is set (in the EPD GUI) is set to OFF.  So, it is normal, not a problem, so far as we know.

If you move the "Move me" red box at the top of the GUI, you can see the voltages to the branches, as seen below:


Branch voltages as reported by the EPD GUI when you slide the "Move me" box.  Here, the EPD is in the OFF state.


Branch voltages as reported by the EPD GUI when you slide the "Move me" box.  Here, the EPD is in the PHYSICS state.


However, the lights on the TUFF box servicing the East side are yellow/orange/red.  When first powered up they are green, but when we check later, they are not.  This has not been seen on previous years.  It seems that both boxes are working okay, however.  The one-wire scan, turning biases on/off, dark current readout.  Still, probably this should be understood.

This is seen in the photos below, this one taken near midnight 20 April and took a photo of the boxes.  (Thanks to Jim Thomas and Gabriel Dale-Gau)






Tim went out and adjusted the voltages on the PSs on 4 April.  This seemed to fix the problem for a while, but apparently not permanently.

When we saw it again, Tim pulled the TUFF, tested it, and reports no problems, so he re-installed it at STAR Friday 19 April 2024.

Late the night of 19/20 April, they were yellow/red/orange again.