I suggest that you call into our support department for assistance @ 1-800-821-2797 or 1-800-835-6100.
Please take a look at this post for a solution to the offline message.
My WorkCentre 6505 has stopped working via USB.
It will no longer print, and the scanner times out. The computer said it was offline.
I deleted the printer driver, and the computer no longer sees the printer when I reconnect the cable.
I have tried rebooting everything, and using 2 different cables. Same result.
It will still print if I use a USB memory stick.
Any suggestions welcome.
Many thanks, Michael