Lexmark MS810n / MS810dn / MS810dtn
From the home screen, navigate to:
> Settings > General Settings > Timeouts > Sleep Mode
In the Sleep Mode field, select the number of minutes the printer is idle before it enters Sleep mode.
Apply the changes.
Here are troubleshooting steps if a Lexmark laser printer or multifunction product is unresponsive from sleep mode.
31.40 or 31.60 errors appear when exiting sleep mode