CS8000i losing its settings? And a maintenance message question?

We have a CS 8000i here in the shop with an interesting problem. If you power off the machine or sleep it over night, when it boots back up it has an error code of C0180 which points to an eeprom code. Along with that it goes back to metric and the destination model goes to Taskalpha. After swapping out boards to troubleshoot with no luck. We tried the battery for s&g, now we get an 0840 code and the clock and times reset. We can reset all the errors but when you power off over night or a few hours the problem reoccurs. So I'm leaning toward bad main pwb eeprom and code dimm. Anyone else run into a problem like this?

Also there is a message about "Time for Maintenance (T)" on the display.. What is that? All the maintenance counters have been cleared after we PMed the machine and changed all the feed rollers. Can't find anything about it in the SM.

Thanks