prints come out with weird horizontal streaks or missing colors, even after cleaning.

Diagnosis

The appearance of horizontal streaks or missing color blocks on the Brother MFC-J4535DW is caused by "nozzle dropout," where specific microscopic orifices in the printhead are obstructed. Because the INKvestment series uses high-capacity tanks, ink can settle or dry out if the machine sits idle for extended periods, creating a hardened plug of pigment that prevents ink from reaching the paper. This is not a software glitch or a paper setting issue; it is a physical blockage. When the printhead fires, the ink should form a perfect droplet. If the nozzle is partially clogged, the ink "tails" or streaks; if fully clogged, you get white gaps (missing lines) in the print. You can confirm this by printing a "Print Quality Check Sheet." If any of the four color grids (CMYK) have missing segments or "holes" in the pattern, the printhead is physically obstructed.

How to Fix It

When standard cleaning fails, you must perform a Power Cleaning sequence to force high-pressure ink through the nozzles. Follow these exact steps:

1. Press the Settings (wrench/screwdriver) icon on the touch screen.
2. Navigate to Maintenance and select Cleaning.
3. Select Print Head. When prompted for the color, select All to ensure all four channels are flushed.
4. After the cleaning cycle completes, the printer will ask you to print a Quality Check Sheet. Do this immediately.
5. If the sheet still shows gaps, do not simply repeat the cleaning. Instead, navigate to Maintenance > Cleaning > Power Cleaning.
6. The machine will perform a much more aggressive purge. This process takes approximately 5-10 minutes. Do not power off the machine during this cycle.
7. Once finished, print another Quality Check Sheet. If the gaps are smaller but still present, let the printer sit for 2 hours to allow the ink to soften the remaining clogs, then run one final standard cleaning cycle.

If That Didn't Work

• Manual Printhead Flush: If the software cycles fail, the ink may be completely dried. Remove the ink cartridges and use a lint-free swab dipped in a 50/50 mixture of distilled water and isopropyl alcohol. Gently dab the rubber wiper blade and the area where the printhead rests to remove dried ink buildup that may be smearing across the nozzles.
• Air Bubble Purge: Sometimes air enters the ink lines, especially after replacing cartridges. Remove the cartridges and gently shake them to settle the ink. Reinsert them and perform the "Power Cleaning" again to push the air pockets out of the internal tubing.
• Check Vent Holes: Inspect the top of the ink cartridges. Ensure the yellow pull-tabs were completely removed and that the small air vent holes are not blocked by adhesive residue. If the cartridge cannot "breathe," it creates a vacuum that prevents ink from flowing, mimicking a clog.
• Printhead Alignment: If the streaks are present but the colors are all there, the issue may be misalignment rather than a clog. Go to Settings > Maintenance > Alignment and follow the on-screen prompts to calibrate the head position.

Heads Up

• Avoid Over-Cleaning: Do not run the "Power Cleaning" more than three times in a 24-hour period. This process puts significant wear on the waste ink pads (maintenance pads) and can cause the printer to trigger a "Waste Ink Full" error prematurely.
• Print Regularly: To prevent future clogs, print one full-color page at least once every 7-10 days. This keeps the ink moving and prevents the pigment from drying in the nozzles.
• Use Genuine Ink: Third-party inks often have different viscosities and surface tensions, which can lead to more frequent clogging or leaking in the MFC-J4535DW's specific printhead architecture.
• Power Management: Always leave the printer plugged into a surge protector and avoid turning it off via a power strip. Using the official power button allows the printhead to "park" in a sealed position, which prevents the nozzles from drying out.