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dramsey · (This post was last modified: 12-24-2015 11:05 PM by dramsey.)

I've repaired a number of 65/67/97 card readers, but the on this 97 is stumping me: although it's got a nice "pull"-- that is, after replacing the goopy rubber wheel, cleaning the head with alcohol, and lightly lubing the worm gear, the card goes through evenly, in fact better than the other 97 I have-- I always receive an ERROR, even on known good cards.

My other 97 has a somewhat inconsistent pull, but reads cards perfectly. I'm worried that it might be an electronic problem although I've never run across one of these before.

Second question: paper is not feeding through the printer. The plastic gear that often disintegrates is fine (and I have a metal replacement when needed); it seems to be that the plastic pinch roller with rubber grips isn't pulling the paper through well. Any source for replacements, or recommendations on repair? I've never dealt with this problem before...

quantalume · (This post was last modified: 12-25-2015 02:44 AM by quantalume.)

Regarding the card reader, is it possible that the alignment of the card to the head is not as it should be? Admittedly, this is hard to do if it is assembled correctly. Are all of the nylon balls in place? Have you tried writing and then reading back the same card? Check to make sure none of the head wires have come loose.

The printer mechanism in the 97 is very similar to the one found in the 82143A for the 41C, which is readily found at a fair price and can be used as a parts donor if necessary. The drive wheels are specially molded over ridges in the plastic drive assembly, but I've successfully used standard O-rings to repair them after removing the remains of the original wheels. However, you have to completely disassemble the mechanism to repair it, a royal PITA.

Paul Berger (Canada) · 12-25-2015, 03:01 AM

(12-24-2015 11:03 PM)dramsey Wrote: Second question: paper is not feeding through the printer. The plastic gear that often disintegrates is fine (and I have a metal replacement when needed); it seems to be that the plastic pinch roller with rubber grips isn't pulling the paper through well. Any source for replacements, or recommendations on repair? I've never dealt with this problem before...

I have repaired a few like this by removing the old hard and crumbly tire on the feed and shaving off the plastic ridge and then slipping a bit of silicon tubing on to replace the tire.

Marcus von Cube · 12-25-2015, 11:32 AM

(12-25-2015 03:01 AM)Paul Berger (Canada) Wrote: I have repaired a few like this by removing the old hard and crumbly tire on the feed and shaving off the plastic ridge and then slipping a bit of silicon tubing on to replace the tire.

A much simpler fix which sorta works is to put some duct tape around the wheel. You can put it on without dismanteling the printer.

TASP · 12-25-2015, 03:41 PM

Duck tape ?

Duck tape in an HP calculator ??

BLASPHEMY !!!

Wink

Dave Frederickson · 12-25-2015, 04:08 PM

The 97 Service Manual has an extensive section on card reader troubleshooting. To adjust the motor speed it may be necessary to substitute a resistor value so some folks have wired in a trimpot to make it easier. The manual also describes the use of a magnetic developer to visualize the track length.

dramsey · 12-25-2015, 04:55 PM

(12-25-2015 02:40 AM)quantalume Wrote: Regarding the card reader, is it possible that the alignment of the card to the head is not as it should be? Admittedly, this is hard to do if it is assembled correctly. Are all of the nylon balls in place? Have you tried writing and then reading back the same card? Check to make sure none of the head wires have come loose.

Yep, all the little plastic balls are in place, as are the two copper tension springs, although I will double check that.

Quote:The printer mechanism in the 97 is very similar to the one found in the 82143A for the 41C, which is readily found at a fair price and can be used as a parts donor if necessary. The drive wheels are specially molded over ridges in the plastic drive assembly, but I've successfully used standard O-rings to repair them after removing the remains of the original wheels. However, you have to completely disassemble the mechanism to repair it, a royal PITA.

Yeah, I figured it was something like that. Still, how much harder could it be than disassembling the card reader?

quantalume · 12-25-2015, 05:59 PM

(12-25-2015 04:55 PM)dramsey Wrote: how much harder could it be than disassembling the card reader?

You'll see. ;-) Be very careful that you don't damage the flex strip when you remove the print head.

Massimo Gnerucci · 12-25-2015, 06:51 PM

(12-25-2015 03:41 PM)TASP Wrote: Duck tape ?

Duck tape in an HP calculator ??

BLASPHEMY !!!

**Katie Wasserman** · 12-25-2015, 07:25 PM

(12-25-2015 11:32 AM)Marcus von Cube Wrote: A much simpler fix which sorta works is to put some duct tape around the wheel. You can put it on without dismanteling the printer.

I thought that duct tape was mostly an American quick fix methodology Smile

I need to give this a try on my 97. Thanks for the tip!

Marcus von Cube · 12-25-2015, 08:57 PM

(12-25-2015 07:25 PM)Katie Wasserman Wrote: I thought that duct tape was mostly an American quick fix methodology
I need to give this a try on my 97. Thanks for the tip!

I read about it in the MySilicium forum (in French). I had to look up "chatterton" to find out what was meant. Smile

Dwight Sturrock · 12-25-2015, 09:09 PM

(12-25-2015 03:41 PM)TASP Wrote: Duck tape ?

Duck tape in an HP calculator ??

BLASPHEMY !!!

That is hilarious!

If it's DUCT tape, it's actually ok to use on an HP.

quantalume · 12-25-2015, 10:27 PM

Just to be absolutely clear about things:

Duct tape is a generic term referring to tape formed by laminating polyethelene, cloth and a strong adhesive.
Duck tape is a trademarked brand of duct tape
The actual tape often used by HVAC professionals on ductwork is thin, adhesive-backed aluminum.

I do not think type #3 would be at all effective in repairing calculator printer feed rollers.

Katie, didn't you write up an exhaustive description of rebuilding a 97 printer somewhere?

cruff · 12-26-2015, 02:38 AM

(12-25-2015 10:27 PM)quantalume Wrote:

The actual tape often used by HVAC professionals on ductwork is thin, adhesive-backed aluminum.

I do not think type #3 would be at all effective in repairing calculator printer feed rollers.

No, but it is effective for EMI suppression.

**Katie Wasserman** · (This post was last modified: 12-26-2015 03:38 AM by Katie Wasserman.)

(12-25-2015 10:27 PM)quantalume Wrote: Katie, didn't you write up an exhaustive description of rebuilding a 97 printer somewhere?

Not me. We've talk about this before and here are a couple of very useful threads to read from others who have found good solutions: one, two

quantalume · 12-26-2015, 04:03 AM

(12-26-2015 03:37 AM)Katie Wasserman Wrote:
(12-25-2015 10:27 PM)quantalume Wrote: Katie, didn't you write up an exhaustive description of rebuilding a 97 printer somewhere?

Not me. We've talk about this before and here are a couple of very useful threads to read from others who have found good solutions: one, two

Wow, those are some nice photos by Ignazio. It never ceases to amaze me the lengths people will go to in order to save vintage HP gear. I've found that, if you use the right size O-ring, you can simply slip it over the plastic drive assembly to the outside of the ridges, and it will stay in place.