Printhead appears to be missing not detected or incorrectly installed

"Peter I am sure this does not help you much, but I have the same issue on a T120 and have gone through the same things as you. 2 print heads, a new carriage assembly with associated cables. I checked all cables and contacts with a multimeter and cleaned them prior to these purchases. This is an expensive printer but I am about to throw in the towel and junk it. HP is less than forthcoming with any possible answers. I even asked what components could cause this failure mode. After hours of reading a technical manual I am no closer to the answer. The manual says nothing other than re-seating the print head, then replacing it.

Other than a main PCB which is also expensive, or maybe corrupt firmware I am at wits end. I have done troubleshooting and repair on CNC milling machines, Lasers and many other types of equipment. I have never hit the situation where a company would not try to help diagnose a piece of equipment. I find it very frustrating. I will post again if I find an answer.

Todd"

That may be but mine did the same with OEM ink.

"I have exactly the same problem on my HP 8620 . Also checked the contacts and so on. I think it is a software issue. The latest firmware update is probably incompatible or has a bug.

To verify this I want to go back to the former firmware version.

Does anybody know how to do this?"

Non OEM Ink ruins the printer period. Not even a new prinhead will save it. Throw the printer in the trash dumspter and go buy a new one and never use non OEM products or generic ink/toner EVER.

"Exactly my story with an HP 8620. I’ve followed HP solutions (reseat and reset), I’ve cleaned contacts and … purchased a new printhead on EBay from China. No joy. One additional item — I happen to own two of these babies, one at home, one at the office. Can you guess? When I change the printheads, the good one works in either printer!

Now … I understand the view that third party ink breaks these printers. If so, shame on HP. I’m afraid I don’t buy the argument that a piece of hardware I own should be chained to an over-priced consumable. There should be some rights and decision left to the consumer, so I’m willing to protest if that’s the case.

And … the fact that the missing or undetected printhead error message follows the bad printhead isn’t evidence that this is caused by ink.

But in the end, I still have a printer that doesn’t work, one from a supposedly reputable manufacturer and not a cheap throwaway model either. I really don’t want to commit a needless environmental atrocity and send this thing to the landfill. (I’d also be less than responsible sending my car to the junkyard the next time it needs a windshield wiper!)

Come on HP!!"