I know what worked so far, but reseating the cables should stop it from happening again. Reboot just resets the connection, but if the connection is poor for any reason, nothing is resolved and it will simply happen again. Reseating the cables that connect it to the MFP is enough to scratch/scrape the pins if they have for any reason degraded/corroded etc.
Thanks Joe. I did turn it off / on and the problem went away...for the time being. Called to have it serviced by an authorized tech next week. Will let you know what they find.
Fax has no output but if it can't fax or copy, both require the scan unit to function, so if it can print while it can't fax/scan/copy, shut it off, reseat all cables going to the upper scanner/adf portion and turn it back on.
If that doesn't get it, call for service, something is broken
Grayed Send button in Fax & Start button in Copy. A shutdown / restart fixed it. Just started happening this week. Will call for service from vendor if I can't figure this out.