Lexmark CS510
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.
Card Authentication ? Card Reader Does Not Respond when Printer Is in Sleep Mode