Can you keep using it?
Can you keep using it?
Contact customer support if any of these apply
- !31.66 repeats after reseating the imaging unit.
- !The printer cannot clear the code after a clean restart.
What to check first
Step-by-step checks
- 1
Consumable check
Power off the printer and remove then reinstall the toner cartridge and imaging unit.
Start with the official recovery step before moving on to parts or deeper servicing.
- 2
Safe first step
Confirm the installed supplies are genuine Lexmark parts.
- 3
Safe first step
Check date, time, and firmware before retrying.
Background
What this message usually means
Lexmark uses 31.66 for a missing or unresponsive imaging unit. The official steps are to verify genuine supplies, reseat the toner cartridge and imaging unit, confirm date and time, and update firmware if needed.
Before the message
What users usually notice first
Messages like this often appear after the printer fails one of its normal startup, supply, or paper-path checks and cannot return to ready state cleanly.
Diagnosis
Likely causes
The imaging unit is not fully seated.
A non-genuine or faulty imaging unit is not responding.
The printer needs a firmware or date/time refresh before the supply check clears.
Service
When service or replacement is more likely
- -Lexmark treats this as a 31.6x imaging-unit fault rather than a paper jam.
Avoid wrong turns
Common misreads of this message
- -Treating the message like a confirmed failed part instead of a support clue about which system has stopped the printer.
- -Assuming any supply-related wording means the next step is automatically to buy a cartridge, toner, drum, or printhead.
- -Assuming no physical path issue exists just because no full sheet is visible at first glance.
See also
Related codes in this family
Explore more
More Lexmark printer families
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Helpful guides for this problem
Boundary
When to stop troubleshooting and move to support
Use the message once to classify the problem, then move to support if the printer still cannot return to ready after the first safe checks.
Keep browsing
Where to go next
Source notes
Lexmark's 31.6x guidance treats 31.66 as a missing or unresponsive imaging unit and recommends reseating the supplies, checking date and time, and updating firmware if needed.
Built around official Lexmark support pages for the CS/CX 310/410/510 family. Code behavior can still vary slightly by exact model, installed options, and firmware generation.
Printer error codes can vary a little by firmware, region, and exact model variant. Use this guide as a family-level starting point and stop if the next step would require disassembly or service-mode changes.
Known family variants: CS310, CS410, CS510, CX310, CX410, CX510
Last reviewed: 2026-04-12
Reference: Open reference