my brother inkvestment printer is printing really blurry or streaky, even after running the head cleaning

Diagnosis

The blurry or streaky output on the Brother MFC-J4335DW is typically caused by "partial nozzle occlusion." Because this model uses high-capacity INKvestment tanks, ink can settle or dehydrate within the microscopic nozzles of the print head if the printer sits idle for several days. When a nozzle is partially blocked, it cannot maintain a consistent droplet size, leading to "railroading" (white lines through the image) or "bleeding" (blurry edges where ink smears across the page).

The reason the standard cleaning cycle often fails is that it uses a low-pressure vacuum to pull ink through the head. If a dried ink plug has formed, this pressure is insufficient to break the surface tension of the clog. You can confirm this by printing a "Print Quality Check Sheet." If you see gaps in the specific grid patterns for one color (e.g., Magenta) but not others, you have a localized clog. If all colors are streaky, the issue is likely a degraded print head belt or a misalignment of the print head carriage.

How to Fix It

To resolve deep clogs without wasting an entire tank of ink, follow this specific sequence to force a deeper purge of the print head system.

1. Press the Settings (wrench/screwdriver) icon on the LCD touchscreen.
2. Navigate to Maintenance and select Print Head Cleaning.
3. When prompted for the cleaning level, do not select 'Standard.' Select Strong. This uses a higher volume of ink to push through the nozzles.
4. The printer will prompt you to select the colors. Select All to ensure the waste ink pad is properly primed.
5. Once the cycle completes, do not print a photo immediately. Navigate to Maintenance > Print Quality Check Sheet.
6. Print the sheet and examine the grids. If any grid is missing blocks, repeat the Strong cleaning cycle exactly one more time.
7. If the streaks persist, perform a Alignment: Go to Settings > All Settings > Print Quality > Alignment. Follow the on-screen prompts to select the number that looks the straightest; this fixes "blurry" text caused by the print head firing at the wrong angle.

If That Didn't Work

• Manual Print Head Soak: If the 'Strong' cleaning fails, the ink has likely solidified. Power off the printer and open the scanner cover. Gently move the print head to the center. Dampen a lint-free microfiber cloth with 99% isopropyl alcohol or a dedicated print head cleaning solution. Place the cloth on a strip of paper towel and manually slide the print head over the cloth, letting it sit for 10 minutes to dissolve the dried ink on the exterior of the nozzles.
• Check Ink Tank Venting: Ensure the printer is on a completely level surface. If the MFC-J4335DW is tilted, air bubbles can enter the ink lines from the INKvestment tanks, causing "starvation" where the head runs dry even if the tank is full. Level the machine and run two 'Standard' cleaning cycles to purge the air.
• Paper Type Mismatch: Blurriness is often a software setting rather than a hardware failure. If you are using inkjet photo paper but the printer is set to 'Plain Paper,' the ink will over-saturate and bleed. Go to Paper Settings on the LCD and ensure the Media Type matches your actual paper (e.g., Inkjet Paper or Glossy).
• Hardware Reset: Perform a hard power cycle. Unplug the power cord from the wall and hold the power button on the machine for 30 seconds to discharge the capacitors. Plug it back in and run the internal "Cleaning" one last time to reset the ink flow sensors.

Heads Up

• Avoid Over-Cleaning: Do not run the 'Strong' cleaning cycle more than three times in a row. Doing so can overflow the internal waste ink absorber pad, leading to a "Print Head Cleaning Limit" error that requires professional service.
• Preventative Printing: To prevent future clogs, print at least one full-color page every 7 to 10 days. This keeps the ink moving and prevents the INKvestment tanks from stagnating.
• Use Genuine Ink: Third-party inks often have different viscosity levels. Using non-Brother inks in the MFC-J4335DW can lead to more frequent nozzle clogs and may void the warranty on the print head.
• Dust Protection: Keep the printer covered when not in use. Dust settling on the print head rail can cause the carriage to jitter, which manifests as vertical streaks or blurry text.