Print the manufacturer's diagnostic, quality or nozzle-check page on supported plain paper and compare it with the model's examples. If that page is clean but one file is poor, inspect the application, file, media and print settings. If the diagnostic page has missing lines, bands, smears or alignment errors, follow only the exact model's documented supply, cleaning or alignment procedure and re-test after each step. Unnecessary cleaning consumes ink and paper.
Let the defect pattern guide the next check
| Observation | Check first | Important boundary |
|---|---|---|
| Faint or missing colour | Diagnostic pattern, supply status and correct media setting | Do not assume every inkjet uses the same head-cleaning sequence |
| Regular horizontal bands | Nozzle or quality test, paper setting and documented alignment | Repeated cleaning is not a cure for every mechanical defect |
| Vertical streak, smear or repeated mark | Fresh test page, paper condition and defect spacing | Do not touch drums, belts or hot fuser surfaces |
| Text is sharp on a test page but poor in one file | Application, scaling, resolution, font and export settings | The print engine may be working correctly |
| Skew, wrinkles or scuffs | Paper size, guides, curl, moisture and supported media | Forcing unsuitable media can damage the paper path |
Use one measured change at a time
- Keep one defective sample and note the paper, application, colour setting and time.
- Load supported, dry plain paper and print the exact model's diagnostic or nozzle-check page.
- Compare the pattern with the manufacturer's guide; confirm supplies are the correct type and installed without a warning.
- If the diagnostic is clean, test another file and application before changing printer hardware settings.
- If the diagnostic shows a supported maintenance condition, run only the documented cleaning or alignment step and print a fresh comparison page.
- Stop when quality returns. Do not run repeated deep or power-cleaning cycles without the exact model guidance because maintenance consumes ink and fills maintenance components.
- Escalate persistent defects with before-and-after samples, the diagnostic page, supply details and the exact steps already attempted.
Protect the printer and the evidence
HP's diagnostic workflow and Epson's nozzle-check guidance both begin with evidence rather than automatic part replacement. Procedures differ by inkjet, ink-tank and laser design, and even within a brand.
Do not use unapproved solvents, compressed air inside toner areas, sharp tools in nozzles or internet reset codes intended for another model. A leak, smoke, burning smell, repeated mechanical noise or damaged cable is a stop condition.
Sources and further reading
Technical statements were reviewed against these references. External pages may change after our review date.
- Print Head Maintenance — Epson Support
- Interpret the Print Quality Report — HP Support