Problem(s) Encountered:

Never saw any error messages, just a blank quad in every data set.

Starting with image #58 (taken at UT 07:53), the upper right (NW) chip appeared to stop collecting photons. I’ve no idea why this happened (it was an unremarkable star/obsrvation otherwise), but I was able to manually shift all of my targets onto one of the three normally-functioning disks. .

Solutions:

Bad connectivity of the cable attaching the detector to the HE.  Replaced locking collar on cable.