Canon PG-745 and CL-746 Cartridges Not Printing After Refill? Here's What to Do

Question:
I followed your tutorial "How to Start Making Canon Spongeless Refillable Cartridges: PG-240 CL-241 PG-245 CL-246" and tried it with my Canon 2577s printer using PG-745 and CL-746 cartridges. After using the suction tool, everything seemed fine. But when I reinstalled the cartridges, the black one wouldn't print at all-only blank pages came out. For the color cartridge, only cyan and yellow print, but magenta doesn't. I checked the cartridges, and they're not clogged-when I rubbed them on tissue, all colors, including black, appeared. What could be wrong? Are the cartridges damaged?
(Watch the video on YouTube)

Answer:

1. Understanding the Symptoms

You mentioned that the PG-745 black cartridge isn't printing at all, while the CL-746 color cartridge prints cyan and yellow but not magenta. You also confirmed that ink does appear on a tissue when you rub the nozzles, which indicates that ink is present and the nozzles aren't completely blocked. This is a key clue: the issue likely isn't a clog, but rather a connection or pressure problem between the printhead and the cartridge nozzles.

2. Possible Causes

Here are the most likely reasons for this behavior:

• a. Air trapped in the cartridge chamber:
  Even if ink appears on the tissue, an air bubble inside the outlet channel can prevent proper ink flow to the nozzles under pressure. This often happens after using a suction tool or during refilling if air enters through the vent hole.

• b. Cartridge electrical contact issue:
  The printer relies on electrical signals sent through the gold contact pads on the cartridge. If these contacts are dirty, oily, or slightly misaligned, the printer may "think" the cartridge is installed but won't trigger the nozzles to fire ink.

• c. Printhead overheating or protective mode:
  Canon cartridges that contain built-in printheads (like PG-745 and CL-746) have thermal resistors that generate heat to eject ink. If the cartridge was run dry even briefly, these resistors can overheat and cause partial or complete printhead failure.

• d. Incomplete priming after refill:
  Sometimes, especially after suctioning, a small air gap forms right above the nozzle plate. This can prevent ink from being drawn properly during printing.

3. Steps to Fix the Issue

Try the following steps before concluding that the cartridges are bad:

1. Re-prime the cartridges using the suction tool again, but this time make sure to draw ink until you see a continuous stream with no bubbles. Then wipe the nozzle plate clean with a lint-free tissue.

2. Check the vent holes (top of the cartridge) and ensure they are open. A sealed vent hole creates a vacuum lock, preventing ink flow. You can poke gently with a needle if the vent appears blocked.

3. Clean the electrical contacts both on the cartridge and inside the printer carriage using a lint-free cloth lightly dampened with isopropyl alcohol. Allow them to dry completely before reinstalling.

4. Perform a deep cleaning cycle through the printer software (on your computer's maintenance tab). This helps re-prime the nozzles and remove air from the printhead.

5. Run a nozzle check pattern. If black still doesn't appear, try slightly warming the nozzle plate with a hairdryer for a few seconds (low heat setting). This can help reflow any dried ink inside the printhead.

If none of these steps restore normal printing, it's possible that the printhead resistors inside the black or magenta channels have failed due to overheating. Unfortunately, this means the cartridge will need replacement, as Canon integrated printhead cartridges cannot be repaired once the nozzles are electrically burnt out.

4. Preventing Future Cartridge Failures

• Always refill before the cartridge runs completely dry.

• Store refilled cartridges nozzle-side down in a sealed container to maintain moisture.

• Avoid long idle periods between uses; run a small print every few days to keep ink flowing.

• When using the suction tool, stop as soon as you see continuous ink flow-over-suction can introduce air or damage the internal sponge seal.

Addressing printer issues can be a complicated affair due to the hands-on nature of the problems. Therefore, we're not able to provide remote troubleshooting, suggestions, or support for printer repairs. We offer an in-person evaluation and repair service at our local diagnostic facility (https://bchtechnologies.com/printer-repair-service). Due to high demand, our repairs are handled on a first-come, first-served basis, and it may take a few weeks before we can process drop-offs. Our services cover both complete printer repairs and individual component servicing, with detailed guidance provided for each case. However, we understand that our rates may not be the most economical, so we highly recommend exploring self-help options. You can start by visiting our YouTube channel (https://youtube.com/@bchtechnologies). Use the search icon next to "About" to find specific videos about Canon cartridge maintenance and troubleshooting. YouTube may also suggest additional helpful content from other creators.

Thank you again for reaching out and for supporting BCH Technologies. Your engagement helps us continue to share technical expertise with the printing community worldwide.