Went to rim-tower to replace the TRH at 20m since it has been reading way off scale, and we have not been able to reset it with ctrl-R or "eio 15 0/1". See https://wiki.ucar.edu/x/6RtaE
and https://wiki.ucar.edu/x/FRdaE
It is connected to port 15. The power monitors for rim and rimup are in ports 14 and 16. I wondered if somehow the power monitors are "back" powering the interface board through their serial cables. To test this, I removed the jumpers labeled FET and +V for ports 14 and 16. The power motes kept coming in, so, as expected, they are getting their power from the battery. After removing those jumpers, I can now power cycle the TRH with eio, and reset it with ctrl-R. After that it looks like the TRH is reporting good data, so didn't replace it.
Prior to removing the jumpers, at some point the rim dsm crashed as I've seen once or twice before on this project, reporting "too much work for irq 4", which is the irq of the second serial board. I believe this happens after an "eio 15 0", which might exacerbate the "back" power problem. See https://wiki.ucar.edu/x/jwtaE
Since this seemed to help rim, I then removed the power monitor jumpers at near, far and base. All those motes continued to report.