OfficeJet Pro 8725 - Cartridges missing/damaged message after cleared paper jam

[RNCRNC]

HP OfficeJet Pro 8725. Windows 10 Home. HP software checked and is up to date.

Had a paper jam. Paper caught in three places - it was a bad one. Had to access and remove via three access portals to remove the jam.  Immediately after the printer display stated "One or more cartridges missing or damaged."

Troubleshooting 1: With power ON, disconnected the power cord and left disconnected for 4 minutes.  Then held down the power button for 30 seconds to assure complete capacitor discharge.  Reconnected the power cord.  Printer turned on immediately, did its diagnostics automatically, and then gave the same message.

Troubleshooting 2: Replaced all four ink cartridges with new OEC HP cartridges.  Unfortunately, the same cartridge error message displayed. 

Please advise on what to do next.

Thanks.

[RNCRNC]

Searched the HP Community posts and found this one, someone with the same problem, albeit with only two cartirdges reported as damaged.  From his last post, it looks like this problem may not be solved.

Link:

https://h30434.www3.hp.com/t5/Inkjet-Printing/OfficeJet-Pro-8620-Cartridge-Issue/m-p/7609214

[RNCRNC]

Further search for this problem.

Here's another frustrated HP customer. Same problem, HP replies, but no resolution.

Link:

https://h30434.www3.hp.com/t5/Inkjet-Printing/HP-OfficeJet-Pro-8725-One-or-more-cartridges-are-missi...

[RNCRNC · Accepted solution]

Well, I got lucky.

Following HP's posted directions, I removed the printhead.  The ink delivery area on the bottom of the printhead was smeared with ink, partially dried.  I wiped off all that I could with tissue and then cleaned the area with a Q-tip wet with rubbing alcohol.  I also used a clean Q-tip with alcohol to clean off all the gold contacts on the back of the printhead and on the four cartridges after I removed them from the printhead. I noticed that the Q-tips had a grey discoloration, indicating to me that there was some dirt or oxidation on the contacts.

After reinstalling the printhead and the four cartridges, the printer recognized the cartridges as genuine.  All functions are now working properly.

I researched what else I could do if the simple cleaning did not work.  I'm including these in case someone has the same problem.  YouTube videos were excellent.  Search HP Printer and your model number for videos that might help.  There is one on removing and disassembling the printhead to clean all the contacts, even those hidden on the back of the printer head. There is also at least one video on how to reset the printer.

Good luck to anyone with this problem.  I hope that I've offered someone help.