In my case the replacement printhead did not work, directly out of the package. I tried it on 2 Pixma MX860 printers, on each of which an old printhead worked fine. I was tempted to return it - especially because the printhead as delivered was wet with ink and some other fluid, but found that a printhead cleaning procedure enabled it to function well (for me, this time).
For the procedure you will need: 1. Water; 2. Glass cleaner such as Windex; 3. Rubbing Alcohol; 4. A dish or bowl (plastic or glass or ceramic (or metal?) whose diameter is large enough to accommodate the printhead; 5. A heat source to dry the printhead after cleaning.
Procedure: 1. Spray the printhead liberally with glass cleaner. You may want to direct the spray into the incoming and outgoing ink orifices; 2. Soak the printhead in a water+glass cleaner solution dish for an indeterminate time; 3. Swish the printhead around in the solution to extract from the printhead ink that was presumably used in manufacturer testing; 4. Rinse the printhead off with clean water. Pat its orifices with a towel or paper towel; 5. Dispose of the solution; 6. Repeat steps 1 through 5 until no ink seems to be leaching from the printhead either into solution or onto the towel; 7. Pat the printhead dry with a soft towel or paper towel; Do NOT let the printhead dry any further yet!; 8. Soak the printhead in rubbing alcohol in the dish. Swish it around with the goal of displacing water left in the printhead with the rubbing alcohol. Let it sit in the solution for an hour or more; 9. Repeat step 8 with new rubbing alcohol another time or two; 10. Dry the printhead with non-destructive heat. I used a combination of soft toweling, sunshine and forced air house heat; 11. Try it out again in the printer. I hope that it works for you.
