I am so, so angry. I have a HP OfficeJet Pro 8210 I bought less than a year ago. Last night I realized there was no admin password set. Generated one in LastPass, copied it to the clipboard and pasted it 3 times. once into notepad, twice into the printer web form to configure the password. Set, ok login. INVALID PASSWORD? WTF? Now, I come to find out HP doesn't list any way to remove set passwords. All the resets I've done have come back to the same spot. This is suddenly a paperweight.
@webshaun Try this. Make sure it's not connected by ethernet.
https://support.hp.com/th-en/document/c05225613
From the home screen on the printer control panel, swipe down to open the Dashboard, and then touch the Setup icon.
Swipe up on the display, and then touch Printer Maintenance.
Touch Restore, and then touch Restore Factory Default.
Touch Continue on the confirmation message.
@webshaun if that doesn't work, try this. It's for a different HP printer, but they often have similar firmware, and this was flagged as working for an 8210:
The trick seemed to be not to press the go back during or immediately after reboot. I also think the usb cable was unplugged.
Press the "Go Back" (looks like an arrow) button 5 times in a row
Press Support Menu
Hit the > button to "Reset" Menu
Hit the > button to Partial Reset
@webshaun one more, also from the HP support forums. Similar situation to yours, locked out of the admin password. Similar mechanism, special/partial data reset. This shortened link was created by me and goes to hp.com:
t.ly/MK2T
@formica So it turned out that they have a 16 char limit on their admin passwords. I cut off the last couple chars of my selected password and poof, worked. I'm back in and it isn't a paperweight anymore.
@webshaun thank you for sharing that tidbit, that's very good information. That's the kind of thing that'll drive a person mad - as it clearly did with you. I hope I wasn't patronizing!
The next step was to try and figure out if there was a way to get into a TFTP firmware flash, or failing that, serial-level terminal access. What a pain in the ass. Like it wasn't bad enough they put DRM on their ink.
@formica RIGHT?! If I wasn't a computer consultant, I'd never have figured this out. I was desperate at the point where I started shaving off characters from the password I was confident I sent to the unit.