Clog or something worse in my IP4000 printhead?

[esp75]

I started seeing some horizontal bands in photos I print with my IP4000 earlier this week. I have been trying to figure out what is wrong and how to fix it for the last few days.

The first thing I tried was the cleaning and deep cleaning cycles. This resulted in no change to the photo output results. At this stage, it was frustrating because the nozzle check pattern looked OK at first glance. So I had to keep printing pictures to check the output.

Eventually I noticed that, in the light cyan and light magenta blocks of the test pattern, there were sections with bands in a similar pattern to what I see in the photos. It's weird because the banding does not show up in the entire block. It looks like there are eight adjoining columns printed in the color blocks. The banding appears in the second, fourth, sixth, and eighth columns. Eventually I found a service manual for the IP4000 online. I was able to print the service test pattern which revealed that there was a problem in the light cyan and light magenta. Oddly the pattern for the light cyan and light magenta look identical. They are missing the same lines. The test prints two 4x32 grids for each color. The first grid is missing the horizontal lines in the 12th and 28th column. The second grid is missing the horizontal lines in the 6th and 22nd column.

I checked the FAQ and found the thread on cleaning the printhead and tried the method described by panos in post #4. This did not change the results at all. The service test pattern looked the same as before. There was no change. I then tried again but let the printhead soak on the wet tissue for 30 minutes. Again I saw no change in the service test pattern.

Should I try different cleaning methods? Or is my problem not a clog? I ask because:
1. Any attempts at cleaning have had no effect whatsoever.
2. The light cyan and light magenta are failing in the exact same way.

More possibly relevant info:
1. I have noticed the problem only when printing photos on photo paper. Printing on plain paper looks OK.
2. I use only Canon OEM cartridges.
3. Printing with these ink cartridges worked fine before this week.

Any advice or insight would be appreciated.

 

[ghwellsjr]

Almost always, missing regular patterns in the nozzle check indicate an electrical problem that cannot be fixed except by replacing the print head. If you're lucky, it could be a bad connection between the back of the print head and the carriage it rides in and removing the print head and cleaning the contacts might fix it

 

[esp75]

Almost always, missing regular patterns in the nozzle check indicate an electrical problem that cannot be fixed except by replacing the print head. If you're lucky, it could be a bad connection between the back of the print head and the carriage it rides in and removing the print head and cleaning the contacts might fix it

Thanks for the possible lead, ghwellsjr. Is there anything special I need to do to clean the contacts?

 

[stratman]

Is there anything special I need to do to clean the contacts?

Use a soft pencil eraser or isopropyl alcohol and a lint free cloth/towel.

 

[ROX]

Almost always, missing regular patterns in the nozzle check indicate an electrical problem that cannot be fixed except by replacing the print head. If you're lucky, it could be a bad connection between the back of the print head and the carriage it rides in and removing the print head and cleaning the contacts might fix it

ghwellsir - would you happen to have a picture of this? I'd like to see it for reference to see if I'm having the same problem.

 

[stratman]

ghwellsir - would you happen to have a picture of this? I'd like to see it for reference to see if I'm having the same problem.

Better that you show us the problem.

You may now post images on the forum. Post an image of your nozzle check and also an image that exemplifies your problem. Use the "Upload" seen at the top of the page. You do no need to fiddle with "resize". You could also upload your images to a file service and post the links here for us to see.

 

[ghwellsjr]

Almost always, missing regular patterns in the nozzle check indicate an electrical problem that cannot be fixed except by replacing the print head. If you're lucky, it could be a bad connection between the back of the print head and the carriage it rides in and removing the print head and cleaning the contacts might fix it

ghwellsir - would you happen to have a picture of this? I'd like to see it for reference to see if I'm having the same problem.

Here's what it should look like:

And here's an example of an electrical problem on the upper cyan:

Notice how the top half of the upper cyan block is lighter than the lower half. Other examples would be where it prints like this in quarters instead of halves or where one half doesn't print at all.