Diagnosis
The streaks, horizontal bands, or missing lines of color on your Canon PIXMA MG3620 are caused by partial or complete blockages in the microscopic nozzles of the printhead. This occurs when ink dries and hardens within the nozzles, creating a physical barrier that prevents ink from flowing evenly onto the paper. This is particularly common in the MG3620 because it uses integrated cartridges (PG-240 and CL-241/246), where the printhead is built directly into the bottom of the ink tank. You can confirm this by printing a "Nozzle Check" pattern. If the grid lines are broken or certain colors (like Cyan or Magenta) are entirely absent, the issue is definitely a clog. If the streaks appear as vertical lines across the entire page regardless of the image, it may be a misalignment or a dirty encoder strip, but horizontal gaps almost always point to dried ink in the nozzles.
How to Fix It
To resolve this, you must force the printer to purge the dried ink using the internal maintenance software. Follow these exact steps:
- Load a stack of plain A4 or Letter-sized paper into the rear tray.
- On your Windows PC, open the Control Panel, go to Devices and Printers, right-click the Canon MG3600 series icon, and select Printing Preferences.
- Navigate to the Maintenance tab.
- Click on Cleaning. Run this cycle first. Once complete, print a Nozzle Check pattern to see if the lines are solid.
- If streaks remain, return to the Maintenance tab and select Deep Cleaning. This uses a higher-pressure burst of ink to clear stubborn clogs. Note that this consumes a significant amount of ink from the PG-240 and CL-241 cartridges.
- After the Deep Cleaning cycle finishes, wait 10 minutes to allow any loosened ink to settle before printing another Nozzle Check pattern.
- If the colors are still missing, repeat the Deep Cleaning process one more time. If there is no improvement after two Deep Cleanings, the ink has likely solidified too much for the software to fix.
If That Didn't Work
- Manual Printhead Soak: Remove the ink cartridges from the printer. Fold a paper towel and dampen it with warm, distilled water or a 50/50 mix of isopropyl alcohol and water. Press the bottom nozzle plate of the cartridge firmly onto the damp towel and hold it for 30 seconds. You should see a clear "stamp" of ink appearing on the towel. This manually dissolves the dried ink crust.
- Cartridge Replacement: Because the printhead is built into the cartridge on the MG3620, a failed printhead means the cartridge itself is defective. Replace the CL-241 (Color) or PG-240 (Black) cartridge with a fresh, genuine Canon OEM cartridge. This is the fastest way to resolve the issue if the soak method fails.
- Encoder Strip Cleaning: If the streaks are vertical or the printer is "stuttering" as it prints, the clear plastic strip (encoder strip) running across the width of the printer may have a smudge of grease or ink. Gently wipe this strip with a dry, lint-free microfiber cloth. Do not use alcohol on this strip as it can erase the timing marks.
- Print Head Alignment: Go back to the Maintenance tab in the printer preferences and select Print Head Alignment. This ensures the nozzles are firing at the correct angle, which can sometimes look like "streaking" if the alignment is off by even a fraction of a millimeter.
Heads Up
- Avoid Long Idle Periods: To prevent future clogs, print at least one color page per week. This keeps the ink from drying in the nozzles.
- Use Genuine Ink: Third-party "compatible" inks often have different viscosities and are more prone to clogging the MG3620's fine nozzles.
- Power Down Correctly: Always use the power button on the machine rather than a power strip. This allows the printer to "park" the cartridges, sealing the nozzles to prevent air from drying out the ink.
- Avoid Over-Cleaning: Do not run more than three Deep Cleaning cycles in a 24-hour period. Doing so can overheat the printhead and waste an entire cartridge of ink without further improving the result.