HP 82240a printer barely advancing paper

[Paul Berger (Canada)]

(05-08-2016 10:34 PM)Jlouis Wrote:  

(05-06-2016 08:51 PM)damaltor Wrote:  As a guess, without having opened one: There might be a (rubber?) wheel which should advance the paper. maybe it is broken/gooey/...?

I just opened it, no rubber wheel, just plastic gears.

Hardware wise, nothing is wrong, nothing broken.

Maybe there is not sufficient voltage for the dc motor?

It would help if someone have the circuit schematic for these printers.

Did you take out the two tiny screws that hold the print mechanism in place and turn the print mechanism over? There is indeed rubber wheels on either side that feed the paper, I could see them from the top but they are much easier to see on the under side of the print mechanism. On the under side you will see a black plastic rod with a long curved ridge on it that acts as a cam to advance the paper much like the printer in the topcats, 82162A and 82143A. On either end there is a rubber wheel, if there is none on yours, you just found the problem. The way it works on 82162A and those like it, on one end there is a ratchet that disengages the paper advance wheels during forward motion of the print head and engages to advance the paper on reverse motion.

The one I looked at is a 82240B, but I would hardly think the print mechanism would be any different on a 82240A.

Paul.