HP 82240a printer barely advancing paper

[Jlouis]

Hi all,

I've searched the forum with no help for my problem, so here it is:

One of my 82240a printers is not advancing the paper properly when printing, making the printing lines suporpose, and the print is unreadable.

If I pull gently the paper, the printing is ok.

Does anyone has had this issue and have a clue how to fix it?

Thanks in advance for any help.

Cheers,

JL

[damaltor]

As a guess, without having opened one: There might be a (rubber?) wheel which should advance the paper. maybe it is broken/gooey/...?

[Jlouis]

(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 haven't opened it yet, but I will search for it. I hope someone have already fixed one .

Thanks damaltor.

[ls41028]

I had a similar problem on my HP97, which has a similar paper feed mechanism. The problem turned out to be a small piece of thermal paper down in the feed mechanism. I pulled the roll of paper out, fished the little piece out with a bent paper clip, and it was all back to normal.

If that isn't it, look for posts on the drive gear on the 97 desktop calculator. As I said I believe the 82240a is similar in design.

Good luck!

[Jlouis]

(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.

[cruff]

(05-08-2016 10:34 PM)Jlouis Wrote:  It would help if someone have the circuit schematic for these printers.

Look on http://www.hpmuseum.net/

[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.

[Jlouis]

(05-09-2016 01:21 AM)cruff Wrote:  

(05-08-2016 10:34 PM)Jlouis Wrote:  It would help if someone have the circuit schematic for these printers.

Look on http://www.hpmuseum.net/

Yes, I found a hand written schematics made by Tony Duell, wherever you are, thanks Tony!

And thanks Cruff to point me to the site.

[Jlouis]

(05-09-2016 01:58 AM)Paul Berger (Canada) Wrote:  

(05-08-2016 10:34 PM)Jlouis Wrote:  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.

Hi Paul, I will disassembly it tomorrow, as I'm at work now. Really thanks to the tip, I think the problem is where you said.

Cheers