HACK CANON 570-SERIES INKJET CARTRIDGES TO REPLACE 550-SERIES (FITS MG5550 PRINTER)

I recently bought a box of what I thought were the correct inkjet cartridges for my Canon MG5550 all-in-one printer. Even though they were identical in appearance to the correct ones, I wasn't sure that they were the correct part number. (They were from a charity / thrift shop, so were cheap enough to take the risk.) Unfortunately, when I got home, I discovered that the correct cartridges are the 550/551 series, and these are 570/571 series.

Although the cartridge cases are physically identical and they clip into the printer perfectly, the Canon printer would not accept the alternative cartridges. After some investigation, it transpired that this is because the 'chips' in the cartridges are different between the two versions. (Why the manufacturer would deem it sensible or necessary to electronically differentiate between two otherwise identical cartidges is another discussion altogether.)

Therefore, I wondered whether swapping the PCBs with the ID chips would enable me to use the 'incorrect' cartridges in my printer?

The chips are mounted under a small black blob of epoxy on a tiny PCB attached to the cartridge. Removing the little PCB from the old cartridge and fitting it onto the new full cartridge is simple enough, cutting or melting the four plastic securing pegs and simply pulling it off. I would recommend leaving the orange transit cover on the cartridge(s) during the process to prevent any spills of ink. (The PCB also carries a tiny resistor, capacitor, and the red LED that flashes to indicate the status of the cartridge, so be careful not to damage these components.)

The replacement PCB can be attached by melting the stubs of the pegs with a soldering iron, or just stuck in place with any available adhesive.

This hack has been tried and worked on the three colours and two black versions of the cartridge. So far, the only drawback with this modification is that the ink level is not correctly reported by the printer. On the positive side, it allows the use of alternative cartridges that might otherwise be thrown away, and I can buy either type of cartridge when I see them at the right price, knowing they can be made to work in this printer.

After more than a year, I have had no problems with this hack. However, I have read that the Canon printer remembers the serial numbers of the last few cartridges installed, and can reject re-used ones, so it may be worth keeping the chip PCBs for use on future cartridges, once the printer has 'forgotten' them, just-in-case it decides to get fussy about cartridges it thinks are empty?

As an afterthought, I assume that the same trick could be used in reverse to make 550/551 series cartridges work in later printers which require the 570/571 series cartridges?