White spots on black text and graphics or black spots appear at 94 mm (3.7 in.) intervals.

Print Quality Problem - Spots at 94 mm intervals

Please check the following points to solve the problem:

If the problem is not solved after printing a few pages, the drum unit may have foreign material, such as glue from a label, stuck on the drum. Clean the drum unit. Please refer to the FAQ "Clean the Drum Unit".
The drum unit may be damaged. Put in a new drum unit. Please refer to the FAQ "Replace Drum".

FAQ & Fehlerbehebung