Problem(s) Encountered:

At the beginning of the night I noticed a large number of noise columns in bias frames, but at a very low level of counts.  This happened a few years ago, but I don''t remember if there was a definite cure.  Maybe something with the fiber optic?  I put an example up on ds9 if you want to see it (image 63).  At the end of the night I did a couple more bias frames and the

effect had largely gone away (those are images 400-401 in the

same directory).

Solutions:

This has been an issue that occurs from time to time.  It typically goes away on its own.  That said, I went ahead and shut down the control box for the majority of the morning (it had been on for a number of days by today) to allow the electronics to cool.  I also cleaned both ends of the fiber running to the control PC.  After bringing everything back online, everything looks good.