Troubleshooting: PGI-550, CLI-551 Auto Reset Chips

This article deals with a few common issues that crop up when using compatible refillable cartridges as replacements for Canon PGI-550 and CLI-551 types.

Printer Status indicates Cartridge “may have run out” but still prints

Chances are very high that you have refilled your cartridge before the printer has identified them as being empty (eg: when indicating “low”) and the printer is now confused by the sudden appearance of new ink.

Why this happens:

The chip will only reset once two devices determine that the cartridge should be empty. If one or other of these indicates ink is present the chip will not reset.

To explain further:

There are two ink level recording devices used in these and many earlier Canon printers. First is the chip which keeps track of overall use and records any information the printer writes to it. Second is a prism in the base of the cartridge used in tandem with an LED which “sense” when ink in the spongeless part of the cartridge has been used up.

The prism/LED sensor are usually responsible for the printer indicating a “low” ink message and this is written to the cartridge chip. The problem comes when the chip hasn’t reached a point where it believes the whole cartridge empty and you, the user, have topped up the cartridge ink so that the prism is now reporting ink.

Understandably the printer gets confused because the chip is reporting that the prism indicated “empty” and then doesn’t. The printer is programmed to understand that this means a potential fault with the cartridge (hence the error) and more importantly the reset will not take place because neither prism nor chip is indicating “empty”.

Solution:

You really have two choices…

1. Accept that your ink levels aren’t going to reset and keep topping up regularly
2. Allow your cartridge to reach a true “empty” point before refilling

Correct Process for Refilling & Resetting

Assuming you have primed the cartridges properly when you first started, simply wait for the cartridge to indicate as “empty” before removing and then refilling as follows:

1. Remove cartridge and attach orange clip (to seal the outlet port)
2. Remove fill plug
3. Pour ink into cartridge then allow cartridge to stand for 1-2 minutes
   (This allows the sponge to absorb ink from the spongeless section of the cartridge)
4. Top-up the cartridge with more ink until full.
5. Replace fill hole plug
6. Carefully remove orange clip and hold cartridge horizontally (outlet down) over some absorbent kitchen paper towel or similar
7. Allow the cartridge to stabilise its internal pressure by dripping for a few seconds
   (If cartridge continues to drip without slowing after 10 seconds check the fill plug!)
8. Once ready, place in printer or re-attach orange clip for storage

Ensuring the cartridge is at full capacity and allowing the cartridge to run down to empty rather than topping up regularly will allow the chip to reset properly and avoid the errors noted above.