MP610 new printhead bad test print mystery!

http://imgur.com/a/pzIH8

Original print head failed, so I ordered a new one. Ran a test print and got a bad result, which is the first image in the link above.

Got a suggestion to get a new PGBK cartridge, which I did. That test print is the 2nd image--terrible all around, except that the density of the PGBK lines that appear is better.

Got another replacement print head and of course used the new PGBK cartridge--3rd image.

Main question, what's going on with the two missing columns in the PGBK area? Sub question, why did the overall quality fall so much for the 2nd test print?

I would suspect an electronic problem given the "orderly" printout.

This is most likely a logic board failure - ie an electrical failure unrelated to the print head. It may be the logic board malfunction has caused a failure in your print heads as well, but you can only know this if you try the print head in a different printer. However, it is possible to propagate problems from one machine to another by swapping in a bad print head and creating a logic board failure. I doubt that this would be your situation, but mentioned it in case you are thinking of trying the print heads in someone else's printer.

The second image with the degraded PGBK print out may very well be complicated by ink flow issues as well as logic board failure even though you were using a new cartridge. Or it could have been a widening of the electrical failures as interpreted by or unique malfunction of that particular print head. You do not give us enough information on all you did or the progression of test prints to determine what was happening.

A new print head and a new OEM cartridge should have corrected presumed print head and/or cartridge ink flow issues. But it didn't. That is not good.

The bottom line, based on the information presented, is your printer is borked for precision PGBK printing.

I suggest you look for any ink spot splatter on the transparent timing strip just behind the print head and clean it with a damp cotton tipped swab (Q-tip).

Tom, there is one tiny spot pretty far over on the right, but I can't seem to get it off. There are also about three whitish spots along the belt; they are not ink and I can't imagine what they are. They look like scratches but they are shaped like blobs rather than scratches.

The spot on the far right side belongs there, but the rest of the strip should be clean. This strip is critical in telling the print head where it is along the print path. Any false information caused by dirt, and maybe scratches too, could cause the problem you are having. Could the white spots be some growth, like mold? I would also expect to see the skip on the colors, but who knows just how these things work? Some of our more knowledgeable members may know, or a search may bring more info. Good luck!

Wouldn't a timing strip problem also affect the colored test patterns?

Grandad35 said:

Wouldn't a timing strip problem also affect the colored test patterns?

Click to expand...

This was my thought as well, so I did not postulate the timing strip as the issue.

However, looking at an old thread on timing strip problem - http://www.nifty-stuff.com/forum/viewtopic.php?pid=56408#p56408 - the PGBK portion of the test print does not show horizontal lines while the dye ink portions do. Maybe the issue can be either/or or both areas of the nozzle check can be affected.

A PDF on Timing Strip issues and fixes = http://downloads.canon.com/cpr/software/mf/MP620_TimingStripCleaning.pdf