Affected Products:![](https://publications.lexmark.com/media/ids_assets/images/transparent.png)
Single-Function: C6160, CS820, CS827
Multifunction: CX820, CX825, CX827, CX860, XC6152, XC6153, XC8155, XC8160, XC8162
![](https://publications.lexmark.com/media/ids_assets/images/transparent.png)
Issue Description:
The printer posts a "621.42" or "621.42A" paper jam / "Printer must cool down before printing next page" error message on the control panel following a job completion.
In addition, instructions will appear asking you to open door B to clear the paper path though no paper will be seen.
Explanation:
This error (intervention message) is designed to alert users for possible contamination of the infrared (IR) sensor in the machine.
![](https://publications.lexmark.com/media/ids_assets/images/transparent.png)
Solution:
![](https://publications.lexmark.com/media/ids_assets/images/transparent.png)
Power off the printer and wait for 30 minutes to allow the fuser to cool down.
![](https://publications.lexmark.com/media/ids_assets/images/transparent.png)
Remove the fuser from the printer.
![](https://publications.lexmark.com/media/ids_assets/images/transparent.png)
Using cotton tip applicator (swab), clean the IR sensor located in area behind where the fuser sits in machine.
Note: The sensor surface has a mirrored finish. Little force is required; just gently swab across the sensor's surface.
![](https://publications.lexmark.com/media/ids_assets/images/transparent.png)
Re-install fuser into the machine and close door B.
![](https://publications.lexmark.com/media/ids_assets/images/transparent.png)
Power the printer back on.
Note: Should error persist, please contact Lexmark Technical Support for additional troubleshooting suggestions.
![](https://publications.lexmark.com/media/ids_assets/images/transparent.png)
Still Need Help?
Have the following available when calling Lexmark Technical Support;
Printer model(s)
Printer serial number
LEGACY ID: SO7984