EUVI-A Quadrant Selector Anomaly

A change in brightness was noted for some EUVI 171 Angstrom images starting in 2011. This was determined to be due to a change in the required mechanism delay setting, which fixed the problem. However, the problem persisted on a few occasions when the delay setting was set to the old value:

2011/02/18 - 2011/10/26 171A (most SSR 1 and about half SSR 2)
2012/06/08 - 16 171A (all SSR 1 and most SSR 2)
2013/08/07 - 29 171A (all SSR 1 and about half SSR 2)
2013/08/07 - 29 195A (most)
2013/08/07 - 16 284A (most SSR 1 and SSR 2)
EUVI-A QS Delay Setting Anomoly

STEREO-A Roll Anomaly on 2009/09/10

The following plot shows a comparison between SC roll as measured from EUVI images and the roll value returned from the SPICE attitude files: