HP Laserjet 4050N - Jamming in Duplexer Unit

[donalo]

Hi All,

I have a problem with a LJ4050N when I print double sided to the duplexer it jams in the duplexer. When printing normally the printer is running fine. Pages since last maintenance kit is 137790.
Page appears almost like it has been folded in half when I remove the jam. It's also jamming on every single page, I can't get one page from the duplex unit.

Any suggestions?

Cheers in advance :)

[woodss]

There is a clutch inside the duplexer under the left and right covers, and over time they lose tension.

This clutch is a U shaped, and tensioned by a U shaped spring, my suggestion is to bend the clutch spring to make its tooth that tensions the large gear to make this plastic tooth pressed as firmly as possible without breaking the tooth, becareful that you dont do this.

The duplexer works by a large gear which is around it also is attached a the clutch moves this arm with a brown gear that moves towards the other gears and the clutch swings the arm towards the diffrent gear trains for 2 diffrent phases of operation.

Each side of the duplexer have this clutch, one for the top and for feeding paper to the bottom of the duplexer and feeding the paper back into the printer.

It very much sounds like the clutch is lose and it can be fixed by creating tension inside the duplexer's clutches.