After receiving a FAX, sometimes after sending a fax, my wireless printer (HP Officejet J4680) says it's offline, and I can't seem to get it to re-connect- reconfigured the wireless setting (it's says it's OK), rebooted the printer, the computer (MacBookPro, OS10.6.8) and the router. Sometimes, it just works, even after it had been offline, when I don't use the computer overnight. What can I do to avoid this frustrating issue?
If it's near your router, the easiest solution would be to run an ethernet cable between the printer and router. I'd also try updating the firmware on your router and checking for new printer drivers. This is a tricky issue to diagnose but I'd start with those two ideas.