MP730 "wrong cartridge" error

Well...
I can tell you what I did.

I came up with this "wrong cartridge" problem today, searched around the web -- there are a number of ideas -- and then started off on my own.

Perspective: I bought this MP730 in 2003 and have been filling the same set of ink tanks since then. Never had a problem with that. Don't know offhand how many pages I've printed, but I refill the ink every couple of months.

What I did...
I removed the ink tanks and the print head. The print head area was all gunked up with ink as well as the flanges the print head sits on (still in the printer). I DID NOT dunk the print head in water. Something in me says water and electronics is not a good thing. The refill ink package I buy comes with printhead and cartridge cleaner -- smells like alcohol, but who knows. I used that and a combination of Q-tips and kleenex to clean any ink away from the print head and nearby surfaces. I also dripped some cleaner into the print head holes the ink tanks plug into and then dried off the whole print head assembly. I purposely did nothing else. That way, I'd know if I'd found the solution.

I put everything back together and fired it up. The printer cycled itself, removed the "wrong cartridge" message and stood ready for me to print. Finished, right??? Not so fast.

I printed out a Windows test page.....it was totally blank!!! Pause....printed out 2 more.... blank... Uh-Oh.

So, I lifted the lid on the printer, lifted the print head lever, jostled the print head a little to ensure good contact, put everything back together and printed another Windows test page....PERFECT!!!

Note: some writers mentioned cleaning a switch off to the right in the printer. I looked at that area and it IS pretty gunked up. But I didn't touch it to clean it up. That way I had a better idea of what DID fix it. I left it gunked. Of course, maybe all I really had to do was wiggled the print head and put it back together. But at least my print head is clean now. ;-)

So, that's all I did. Don't know if it wil help you, but it's a start.

I had the same «wrong cartridge» problem and could get it solved. Here is what i did? Following the first instructions from DallasSmith, (1) I put the cartridges-leaver up and removed the 4 ink-cartridges; (2) removed the print-head which is not screwd or hard-attached so all you have to do is carefully take it out of its place (I suggest directing a strong light to this area to understand the parts beeing touching); (3) once outside, the print-head had no ink on the black-cartridge touching area which i believe due to a problem in the black-ink cartridge, since all the other 3 contact areas had a good amount of ink. I assumed that the black-cartridge was not delivering ink which leads to the machine error and forced by hand some black-ink to this area and replacing the black-cartrige by a new one. It solved the error. Additionally, I did also the cleaning of the head. No water, just a kleenex with one or two drops of alchool. In the end, i believe that this was really a problem with one cartridge which the printer could not take ink from. Consider also that this solution may apply to any of the other color ink-cartriges. In conclusion, check the status of the ink-interface between all the cartridges and their socket. If some is too clean, suspect of that cartridge.