I suppose that I've always known that it's unwise to move a used Designjet, especially up stairs, but now I know exactly why:

When you tip this little baby up at a 45 degree angle, then carry it up a lot of stairs, all the ink that has collected in the ink supply stations runs out. Eventually it will get into something important, in this case it's the encoder disk and sensor for the lower rewinder. Soaking out the sensor and disk in alcohol sadly didn't help. I was certain when I powered up. The upper rewinder moves less than one tooth to detect rotation. The lower rewinder spun up to full speed for 5 seconds, then reversed at half speed for 3 seconds ... then throws the error having not detected rotation.

Rewinder Error.jpg