Duplexer problem I just installed a used duplexer for my LJ 4 + printer. The printer works fine in simplex before the duplexer was installed. The duplexer seems to work, but not correctly! I have set up the printer in the Settings > Printers > LJ4+ > Properties > Device Settings > Installable Options > Duplex Unit "Installed" So it should function properly. In duplex mode, paper is supposed to feed into the printer and print the second page first, then it goes through the duplexer and is turned over and the first page is supposed to be printed and the paper exits into the upper finished page tray. What my unit does is to feed the paper into the duplexer first and then turn it over and then print the second page and feed the paper direct to the finished copy tray. Then it prints the first side on a SECOND sheet of paper, without ever sending a sheet through the duplexer. Does anyone know of a sensor or possibly a failed roller that might be the offending part that doesn't send the paper on the correct path through the printer/duplexer combo? Any other ideas?

Hi Mary L,
Good day... This steps may be helpful for you. try sorting one by one steps...below
solution 1:
1.The duplexer side adjust has failed.
2. Turn the printer off and then on.
3. Reseat the duplexer assembly.
4. Replace the duplexer assembly.

solution 2:
1. The duplex printing unit is not functioning.
2. Turn the MFP off, and then turn the MFP on.
3.Reseat the duplexer.
4. Check the connection between the duplexer and the DC Controller.
5. Replace the duplexer.

solution 3:
1. Duplex mechanism failure.
2. Duplex slide adjust has failed.
3. Temporary error.

Hope this solve the problem...
Thanks in Advance.
Hp Error Code 69 Service Errors 69 Printer Repair Message

You've done everything I would have done and more.
How about you installing a DOA duplexer. At this point I would change it again. Is there another printer that you can swap duplexers with?
There is a paper path sensor test (letter H) and manual sensor test . I don't know if the Component test checks the duplexer, but you should be able to find out.
Is the printer still under warranty? Can you call HP or are you an HP tech and you can call 2nd level support.
Just a thought....when you run a Config sheet, does it show the duplexer?

What is the code? This unit does not have a fan in the duplexer nor for the duplexer. The 9500 has a fan housing but there was never a fan put in by the design team. Give the code and I look it up to see the problem.

Hi,
This could be a couple of things, easiest thing to try first is to put a different toner cartridge in, something that has already been opened because it would save you from opening a new one. Another thing you can try is sending a cleaning page through the printer to clean off excess toner from the fuser unit. What happens is over time toner builds up on the lower pressure roller of the fuser unit and after being heated and cooled so much the toner starts to flake off on your print outs. Follow these steps to try to clean the lower pressure roller:

To run the cleaning page manually
1.If a duplexer is installed, open the rear output bin.

2.Press check mark(SELECT button) or the MENU button to open the menus.

3.Use (UP ARROW button) or (DOWN ARROW button) to scroll to CONFIGURE DEVICE, and then press

4.Use or to scroll to PRINT QUALITY, and then press the check button

5.Use (UP ARROW button) or (DOWN ARROW button) to scroll to CREATE CLEANING PAGE for the(LJ 4200/4300) or PROCESS CLEANING PAGE if you printer is a(LJ 4250/4350) then press the check mark

6.Follow the instructions on the cleaning page to complete the cleaning process (LJ 4200/4300
only).

7.If a duplexer is installed, close the rear output bin.

This should help clear some of the flaking toner, if not you might have to replace the fuser unit.

There is a new driver from april 2009 on HPs site which adresses this problem. I installed it, and now everything works fine. You have to download and install it yourself, it doesn´t update automatically.

Some of the rollers inside the printer have becomes slick with paper dust on the surfaces of the rollers. There is a printer cleaner paper available at most office supply stores and online. It is sticky on both sides. You run a sheet through the printer a couple of times and it removes the dust from the rollers. In your case, run the paper through the duplex unit too.

If you really have an HP 4350dtn (d = duplexer), then the duplexer is not connected correctly. Look at the back of the printer for the duplexer. It prtrudes from the back drop down tray and is used to print on both sides. I would pull it out and push it back in to make sure all connections are tight.

Tray number 1 is the manual feed tray in the front of the unit.

In Vista the default s the duplexer is "not installed". Go to Start, Settings, Control Panel, Printers, double-click on the Deskjet, Printers, Properties, Device Settings and set the duplexer to "Installed".

If the duplexer prints the back side upside down in Vista once it is enabled you can get a patch as described here.

Regards,
Bob Headrick, Microsoft MVP Printing/Imaging

What is the exact error message shown on the display ?
Does it makes any strange noise when you start it up ?

ddlaw,

Just exactly is the model of your printer?