Lexmark MS818
The printer or multifunction product (MFP) does not wake up from Sleep Mode even after pressing the touch screen or any of the buttons on the control panel.
Perform a power cycle (power off, wait 30 seconds and then power it on again) on the printer to return its full functionality.
Download and update the printer to the latest firmware.
LEGACY ID: SO7526
Sleep-Print-Sleep Printer Function Now Available on E6 Firmware for the Lexmark MS71x, MS81x, MX71x, & MX81x
Lexmark MS71x, MS81x, MX71x,&MX81x ? 980.11 Service Error Posts when the Device Goes into Sleep Mode