Skip to Content Information Center
Lexmark MS621

Lexmark MS621

The Printer Freezes During Printing and Posts a 900 Firmware Error

Affected products



in the title section above.

Issue description

When a user is printing a document, the printer freezes for a few seconds then restarts with the 900 firmware error.

Possible cause

This issue is considered to be related to memory tuning and will be improved on the latest Firmware update.


To resolve this issue, you must perform Power-On Reset (POR) by manually switching the printer OFF for a minute then powering it back ON.

Still need help?

If you need additional assistance, please close this browser tab or go to the Lexmark support site, type your printer model and locate

Get in Touch with Lexmark! for contact information.
When calling for support, you will need the following:

  • Affected printer model/'s

  • Printer serial number

Please be near the product/s described in this article to expedite the support process and reduce callbacks.


Was this article helpful?