Lexmark CX735
From the home screen, touch Settings > Device > Maintenance > Out of Service Erase.
Touch the Sanitize all information on hard disk check box, and then touch ERASE.
Depending on the storage drive that is installed on your printer, do either of the following:
Note: The ISD is cryptographically erased.
Start the operation.
Note: The process to sanitize the hard disk can take from several minutes to more than an hour, making the printer unavailable for other tasks.
Remove stored information to free up printer memory and avoid printing errors.
Expand the memory capacity of your printer to print complex jobs and collate large print jobs.