OfficeJet 6950 with paper jam followed by 0x6100004a

[BeExcellent]

Hello,

Like many people in this community, I have a HP OfficeJet 6950.

When powering it on, after moving the rollers a couple of times, it complains about a paper jam. I've taken the printer apart and cleaned all the rollers -- there is no paper anywhere. If I click "OK" on the screen, the printhead cleans itself and moves a few times, then gets parked and the error 0x6100004a is displayed.

What I have already tried

1. as I said, checking every single surface of the printer (paper tray, duplex, printhead rollers, ADF) and cleaning all the rollers
2. power cycle the printer several times (unplug, wait 2 minutes, plug back)
3. factory reset (via the Settings menu, as well a semi-full reset via the Service menu) (for users who don't know: to open the Hidden Service menu: press the "back arrow" button 5 times)
4. power down, remove the ink cartridges, power up again without ink
5. firmware upgrade (it's the latest version)

Every time the sequence is exactly the same -- paper jam (not sure *where*) followed by hard error.

My questions are:

• How can I find out which sensor is telling the printer that there's a jam? I suspect that it could just be a stuck/dirty sensor causing a lot of fuss for nothing.
• What's the nature of the 0x6100004a error? What does it mean? Is it due to the paper jam being "unsolved", so the printer locks itself out to avoid damage? That would make a lot of sense, but it would also help a lot to understand why the printer thinks there's a jam.

For users who don't know how to unstick the ink carriage when the printer gives an error

That's a feature of the printer: the ink carriage parks itself to the right and latches onto the cleaning tray. This way the printer becomes safe to being transported without damaging the print head. DO NOT FORCE A MOVEMENT OF THE INK CARRIAGE.

If you want to be able to move the ink carriage, then:

EASY SOLUTION:

1. As soon as the printhead moves during the printer powerup, disconnect the electrical power. Now the carriage is free, you can easily reposition it, change the cartridges, and access the cleaning tray.

HARD SOLUTION:

1. power off the printer and disconnect electrical power
2. move the carriage to the extreme right (you'll find it can be moved just a bit; that will un-latch it)
3. reach for the gear wheels on the left (beware not to damage the connection cable to the printhead) and start turning them. If you turn them in the wrong direction, they'll stop moving. If you turn them in the right direction, the cleaning tray will move from below the ink carriage, and this will unlock the carriage. A few spins are sufficient; you'll see the carriage lower itself onto the carriage rails when it becomes free.