Lexmark C2335/CS531/CS632/CS639 printer platform — 31.40-31.43
Lexmark 31.40-31.43 means a toner cartridge is not installed or seated correctly. The guidance here is specific to C2335/CS531/CS632/CS639 printer platform and the Toner cartridge operation.
Error meaning
A toner cartridge is not installed or seated correctly.
This interpretation is tied to the reviewed family/platform and subsystem. Do not reuse the code by itself on another printer family.
Applies to
C2335/CS531/CS632/CS639 printer platform
- C2335
- CS531
- CS632
- CS639
Common formatting
These are lookup/formatting aliases for this reviewed condition, not separate pages.
- 31.40-31.43
What usually causes it
- This code range identifies one of the toner cartridges as missing or not seated correctly. The suffix selects the affected color/position, so the full code matters when deciding which cartridge to inspect.
- The exact condition recorded for this code is: A toner cartridge is not installed or seated correctly.
- Use the full 31.40 through 31.43 value to identify the indicated cartridge, remove only that cartridge, verify it is in the correct slot and free of shipping material, then reinstall it until it seats normally.
What to try
Check the condition this code actually names
Reseat the indicated cartridge in its correct position.
Isolate the affected part of the workflow
Use the full 31.40 through 31.43 value to identify the indicated cartridge, remove only that cartridge, verify it is in the correct slot and free of shipping material, then reinstall it until it seats normally.
Run a controlled confirmation test
Close the printer and check whether the same suffix returns. If the error moves with a cartridge or disappears with a known-correct cartridge, the supply is more likely than the printer slot.
After each corrective action
Retry the original operation that produced 31.40-31.43. If it works, stop there rather than moving into unrelated troubleshooting.
If the code returns
If one slot reports the same code with multiple correct cartridges, preserve the exact suffix and slot rather than swapping all colors at once.
When service may be needed
Do not bridge cartridge contacts or force an incompatible supply into place. Persistent slot-specific detection failure should be serviced.
Continue with guided troubleshooting
If the printer still is not working after the reviewed checks, carry this verified error context into the guided troubleshooter.
Related information
Verified source
Official four-model User’s Guide (2026 edition) contains the printer error-code section and safety cautions.