My Cannon iP4000's printhead stopped printing magenta ink. Lets just say I highly suspect the Stratitec magenta refill ink I was using of causing the problem.

I could have been a good little boy and paid Cannon $110 for a replacement printhead. This certainly doesn't seem very reasonable since I could purchase a brand new Cannon iP4000 for $180. Thus, I decided to take matters into my own hands and clean out the clogged printhead myself. Now on to the fix!

• This is a picture of the bottom of the print-head. The front of the head is at the top of the image. To clean the head you will have to remove the two screws on the left and right.
• The large slot on the left is the "head" for the pigmented black ink cartridge (Canon BCI-3eBK), it is used for printing text.
• The rectangle with six slots in it contains the heads for the colored dyes.
• I find it interesting that two of them are for cyan, two for magenta and only one for yellow and one for the black dye (not pigmented). This head is used for printing everything that is not 100% black text.
• The clog was not in these heads, but in the cartridge-holder.
• The circle you see around the heads is a reflection of my camera lens.

• This is a front view of the cartridge-holder. You can see I have removed the two screws holding the head assembly to the holder.
• This did not just fall into the position you see here, there is a rubber gasket between the plastic holder and the ceramic head (we'll get to that later).
• The head must be carefully pried up to break the gasket seal; you can see a small lip on the head at the bottom of the picture, use this to pry against. Be VERY careful not to chip the head when doing this!
• You can see some ink remaining on the head and the holes for the ink to get to the head slots. Better shots of this are coming.
• You can see the "stalls" the ink cartridges fit into in the holder. From left to right they are Black Dye, Black Pigment, Yellow Dye, Magenta Dye and Cyan Dye. As you can see, the Pigmented cartridge is much larger than the Dye cartridges.

• This is a shot of the cartridge-holder looking down from the top with the front of the holder at the top of the picture. Again, you can see the stalls for the cartridges, but now you can see the screens which are the transfer points where ink flows from the cartridges to the heads.
• The screens are surrounded by round rubber gaskets to make a tight seal against the bottom of the ink cartridges. The picture is blurred enough so you can't tell the silver dots are actually screens, but trust me okay?
• The two dimmer dots on the far-left and far-right are reflections, as are the other bright spots at the bottom of the picture. I believe my clog was just below the magenta screen.

• This photo is of the cartridge-holder with the front facing the table, displaying the rear of the holder and the head assembly.
• Look closely at the color head; you can see two small white slots in the head slots second in from both the left and right. These are the actual holes the ink flows through to feed each individual color head slot. These are the slots for printing magenta. As you can see, there is no clog here. I tried to get a shot of all the holes through the slots, but failed. It's too bad because it really looks cool!
• Note the electrical contacts on the PC board and the wide reddish-brown ribbon cable that runs almost the full width of the head assembly. Be careful of these, if any of these traces are cut or broken - well, you figure it out.