Diagnosis
The occurrence of blank pages immediately following a cartridge replacement on the Canon PIXMA TR4720 is typically caused by a vacuum lock or dried ink residue within the print head nozzles. When you swap cartridges, air can enter the ink delivery system, creating an air pocket that prevents the new ink from reaching the paper. Because the TR4720 uses integrated print head cartridges (where the nozzles are built into the bottom of the cartridge), the issue is usually isolated to the specific cartridge that isn't firing, rather than a separate permanent print head assembly.
Another common culprit is the failure to fully remove the protective orange plastic tape from the bottom of the new PG-275 (Black) or CL-276 (Color) cartridges. If the vent hole or the nozzle plate is still covered, the ink cannot flow due to atmospheric pressure. You can confirm this by performing a "Nozzle Check" print; if the page is completely blank despite the ink levels showing as full on the LCD screen, the issue is mechanical flow rather than a software or connectivity error.
How to Fix It
- Power off the printer and open the scanning unit/cover to access the cartridge installation area.
- Remove the PG-275 and CL-276 cartridges. Inspect the bottom of each cartridge to ensure the orange protective tape has been completely removed. If any adhesive residue remains over the gold-colored contacts or the ink nozzles, clean it off with a lint-free cloth.
- Perform a "Manual Prime": Dampen a clean, lint-free paper towel with warm distilled water. Gently press the nozzle end of the cartridge onto the damp towel for 3 seconds. You should see a solid, crisp line of black ink or three distinct stripes of color. If no ink transfers, the cartridge is defective or severely clogged.
- Reinstall the cartridges firmly until they click into place and close the cover.
- On the printer's operation panel, press the Setup button (pliers and screwdriver icon).
- Use the arrow buttons to navigate to "Maintenance" and press OK.
- Select "Cleaning" and press OK. Let the printer run its cycle for 2-3 minutes.
- Perform a "Nozzle Check" from the same Maintenance menu to verify the ink is flowing. If the patterns are broken, repeat the "Cleaning" process once more.
If That Didn't Work
- Perform a Deep Cleaning: If standard cleaning fails, navigate back to the Maintenance menu and select "Deep Cleaning." This uses a higher pressure pump to force ink through stubborn clogs. Warning: This consumes a significant amount of ink, so only do this twice before seeking other options.
- Hard Reset the Logic Board: Unplug the power cord from the back of the TR4720 while the unit is still powered on. Wait exactly 60 seconds. Plug the power back in and restart. This clears the internal print queue and resets the ink delivery sensors.
- Clean the Encoder Strip: Locate the thin, clear plastic strip that runs horizontally across the width of the printer behind the cartridge carriage. If a smudge of grease or ink is on this strip, the carriage may "think" it has printed but actually skip the page. Gently wipe it with a dry, lint-free swab.
- Check Paper Settings: Ensure the paper type selected in the print dialog (on your PC or mobile app) matches the actual paper in the tray. If "Photo Paper" is selected but plain paper is loaded, the printer may adjust the ink volume in a way that results in faint or blank output.
Heads Up
- Avoid leaving the printer idle for more than two weeks; the TR4720 nozzles dry out quickly, leading to permanent clogs in the integrated heads.
- Always use genuine Canon PG-275 and CL-276 cartridges. Third-party "remanufactured" cartridges often have poorly sealed vents, leading to the exact air-lock issues described above.
- Never use rubbing alcohol or harsh chemicals to clean the gold contacts on the cartridges, as this can strip the conductive coating and cause "Ink Cartridge Not Recognized" errors.
- If you frequently print high-volume documents, keep an eye on the waste ink absorber levels; once full, the printer will lock and require a service reset.