No scanning, no printing, no xeroxing

It sounds like your Xerox 5855 printer is experiencing a technical issue that is causing black stripes to appear on the printed pages and an error message to be displayed. There are a few things you can try to fix the problem:

1. Check to make sure that the printer is properly connected to the computer and that all cables are securely in place.
2. Check to make sure that the printer is fully operational and that all the necessary components, such as toner and ink, are installed and functioning properly.
3. Check to make sure that the printer driver and software are up to date. You may need to download and install the latest version of the driver and software from the Xerox website.
4. Clean the printer's printhead and roller. This can help to remove any dirt or debris that may be causing the black stripes to appear on the printed pages.
5. Check the printer settings to make sure that the correct paper size and type are selected.
6. If the issue persists, you may want to try resetting the printer to its factory settings. To do this, consult the printer's manual or contact Xerox customer support for further assistance.

If you have tried all of these steps and are still having issues with your Xerox 5855 printer showing black stripes on the printed pages and displaying an error message, you may need to have the printer serviced by a professional. You can contact Xerox customer support for further assistance and to find a service center near you.

https://forum.support.xerox.com/t5/Copying-Faxing-Scanning/Phaser-3635-scanning-lock-message-but-lock-is-not-locked/td-p/177527

my dear you chek toner and change toner tenk

You Really need to have this Machine Cleaned. there is too Much Paper dust On the sensor

Power off then on. If this doesnt clear the problem the power supply i going faulty and will need to be repaired..

LSU stands for Laser Scanner Unit. Depending on the model this should come up only if the services used required scanning such as copy, fax sending, scanning.
nevertheless if this is a continuous message you might need to check the connectors within the scanner which I advise an field call.

XEROX WORKCENTER PE220 , ITS SHOWING LSU ERROR . ITS NOT PRINTING OR COPYING ANYTHING . PLEASE GIVE SOLUTION

Someone installed the "Printing Scout" on this computer. You may need to uninstall or check all the settings in the printer driver. I'm not really familiar with Macs but I know the 8560 inside out, upside down, and backwards.

well..it's a system error code..is this an older machine, by chance?