Where to get ARC Chip for Canon 9000 MKII
Here is what Bob Petruska told me about replacing chips with spares from other cartridges:
"One note here, if a chip fails for you on a good cart that is now flowing 100% 3rd party ink there is no need to start over with a new cart. Just change the chip."
"Look at the cart chip attachment and you will see two small round tabs holding the chip in place. Using an Xacto knife, trim the right side tab off, the left side of the chip just slides under the left tab, no need to trim, and lift the chip off. Do the same to remove the new cart good chip, and slide it in place on the old good cart, it will have some snap in place and hold it appropriately."
So all you need is a spare cartridge with the right ink color chip and to follow Bob's instructions. Keeping empty spares of all the colors, more of the ones you use most, is probably a good idea. If you buy the used empties cheaply on ebay, you don't even have to clean them up and fit them out for refilling. Just keep them for the chips. And you certainly don't need to pay for someone else to have cleaned them up and outfitted them for refilling.
One way to acquire the chips is to buy them on ebay attached to empty carts. But on ebay it is getting hard to find red, green, and black (make sure the black is CLI-8 size, not the larger black cartridge some Canon printers mix with the CLI-8 colors), but they do pop up every now and then. Many of the lots of 50 or 100 or more are just multiples of the 4 colors used in other Canon printers and don't help you with PC, PM, R, G, and CLI-8 Black. I just bought 46 used cartridges with two full sets of all eight colors, one extra black, and the rest assorted among the five colors mostly used, C, M, Y, PC, and PM. Cost was only $22 including shipping. I should be set for a while. Point is the full assortments do come up from time to time.
Oh, and by the way, Bob also says that the office supply stores (like Staples) will give you a $2 store credit for each empty you turn in to them. So if you don't need all the carts you buy in a big assortment, just keep the ones you want and sell the rest. Sweet.