I use my 4880 just for GO on color. I keep Piezoflush in the 7 carts not using GO. These carts were getting low, so time for a refill. After doing so, 5 of 8 carts were not recognized, including the GO cart which was not touched. Having one spare chip for the gO cart, I decided to replace chip, still baffled why the GO cart was not recognized. Since I was an Electrical Engineer in a former life, I decided to dehumidify my studio, as its humidity became low.
After re-inserting the GO cart, I turned on the 4880 an voila, all carts are now recognized. Since removing carts on the 4800 involves moving leavers up and down, I think that these lever movements (as well as those in the subsequent Power Clean), may have caused a static charge build up on some, but not all of the carts.
Another reason to keep studio humidity high.