Mcintosh ma6600 strange signs on display

Hello! The problem is next:
Today I switched on my amp Mcintosh ma6600 and see on display something unusual:
SOURCE: x 0 y /
instead of SOURSE: CD, and
instead of CD2. All another modes displayed as they need to show tuner, phono, rec etc.
Amplifier working well without another problems.
Yesterday all were good.
Maybe someone know what is this?
Thank you!

First, unplug the unit from the wall socket for a minute or two.  Then, plug it back in, turn it on and see if the problem goes away.  If so, good.  If not, go through all your settings, note them down and then do a factory reset.

After you reinstall your settings, check it again.  You should find that everything is back to normal.  If you're still having a problem, you'll have to go through the isolation drill with all the upstream components and identifying anything that might have changed or happened between the time it last worked properly and when you noticed the error.

The preamp section can encounter errors in low voltage or momentary outage conditions.  Usually, just unplugging the unit will take care of it, but sometimes a reset is needed.

Good luck & happy listening!
Wow, yes! It's done! The problem is gone, thank you very much mr.Effischer! I made Master reset and everything became correct.
Thank you!