My HP Officejet 8500 keeps displaying that it's cleaning the printhead in an endless loop

[Rohanross]

I have exactly the same problem. Can someone PM (or present here) the solution to draining hundreds of dollars worth of ink on endless test/cleaning cycles? 

[Mackasx2]

Hi Distinguished Professor.

A friend gave me her HP OfficePro 8500 Model 910A and yes it is doing the loop thing.

I found your answers and thought you may be able to help me by messaging me your fix.  My printer has a keyboard on it so I would appreciate the extra thing you mention in this post.

Thankyou,

Cathy

[Owen1989VU85]

I have a HP OfficeJet 5740 that is also displaying a message that it' is"cleaning the printheads" with an endless loop circleing above the message. Your suggestion to unplug the back-and wall-power cords and then plug them back in after 15 seconds removed the printhead message initially, but when I tried to clean the printheads again using the HP Print and Scan Doctor 5.2, the same message reoccured with a revolving loop above it.

I have been problems with lines printing unevenly in documents. They are wavey and disconnected. I printed a test page that indicated I needed to clean and align the printheads. The color bars on the test page were all solid and uniform except for those from the black cartridge.  That is why I was trying to clean the printheads.  The lines immediately below the color bars on the test page were not straight or connected. Aligning the printheads did not solve this problem.

I think my problem is caused soley by the black print cartridge. I have tried to take the cartridge out and clean it, but this did not solve the problem.  Any suggestions?

[Rohanross]

I gave up and got a Canon Laserjet. HP were unwilling to repair the problem.