Help wanted for HP-97 printer repair

[Kees Bouw]

Hi,

I have started to disassemble my HP-97 printer to fix the paper transport. Unfortunately I can't figure out how to remove the shaft that has the transport wheels attached to it. In the pictures you can see the current state of the printer, the position of the two wheels between which the paper is transported and the shaft ends. The shaft I want to take out (green arrow) can't be moved far enough to slide out of the opening, because the other wheel (blue arrow) is blocking it. Question is, how should I proceed or what have I done wrong?

Kees Bouw.

   
   
   

[Paul Berger (Canada)]

You should be able to push it back far enough to lift it out, I have been able to do that on any I have worked on, but I think you will need to remove the lead screw. there is one C clip holding the gear onto the end of the lead screw, remove it and remove the gear there is another C clip inside the frame, remove it as well the lead screw comes out the opposite side and the white nylon bearing will come out with it. To get the feed rolls out of the head carriage you will need to remove the print head, it is held in place by two screws and a flat piece of aluminum. Be very careful reassembling, the print head is a piece of ceramic and if it is not properly positioned and you tighten the screws on the aluminum retainer you may crack it. I have found from experience it is easier to reassemble it with with the feed rolls in place before mounting it on the lead screw and guide rods. I am guessing you wish to take out the feed rolls because they are hard and smooth and not feeding paper. I have had good success replacing them with silicon tubing, just make sure the tubing does not overlap the ratchet and if you glue it on, be careful you don't get glue on the ratchet. The ridge that runs down the feed roll shaft is a cam that rides in a slot inside the print head carrier when you reassemble make sure it is in place or it will not feed paper.

Paul.

[Kees Bouw]

Hi Paul,

Thank you very much for the detailed advice! I have now been able to take out the feed rolls. I was not sure about what to remove and what not, and also about applying some force to lift out the shaft. Thanks to you it all worked out. Now I will try to find some silicon tube that has the exact same diameter and then put it all back together again. I took lots of photo's so that should not be a problem. Thanks again!

Kees.