Hp-41C card reader - dead

[Vintage63]

Good evening / morning / afternoon everyone.
I have been an HP-41C owner since university, let me think, 38 years ago. Time does fly.
I have 3 Memory Modules plugged into the back of the 'box', I've inserted the Card Reader, 82104A, ehich had been sitting around for years in its box.
Batteries have been replaced a few months ago after the previous ones 'died'.
The card reader does not move at all when I insert a card.
What can I do? I recall that when the card reader was inserted, ages ago, it drained the batteries but then worked properly. This time nothing of the sort happened.
I've read the various tutorials on how to replace the gooey card puller, but nothing about the motor.
Is there any documentation available or anyone that knows what to do ?
I've got no problems at fixing 'old' stuff, in fact I do some fountain pen renovations, so working on it should not be a problem.
If the worst come to the worst I'll bin the reader and that's that.
Thank you
Marco

[aurelio]

Sometimes the motor does not work properly, cause of a defective (loose) clutch
I solved with 41 but also with a 67, fixing the clutch with a drop of glue. This could solve a problem of irregular sliding of the card and then unproper reading.
You can find surfing this Forum and its archive experienced people's solutions and follow them as I did
But have you already checked inside to be sure that the problem is not the classical one?

[teenix]

Being a self contained reader, there is quite a lot going on inside the unit which means many things could be wrong.

If the motor is not coming on at all, the first thing I would check is broken/corroded wiring or connectors. Check the circuit board for corrosion.

If you are handy with a voltmeter then you may be able to check out basic voltages around the circuit.

This is the reader circuit.

http://www.hpcc.org/cdroms/schematics5.0...p82104.pdf

Hopefully it is not more complex otherwise an IC like a ROM may have failed.

If in the end you do decide to bin it, please do it my way, I'd love to play around with it :-)

cheers

Tony

[Vintage63]

good evening, I opened the card reader. Checked contacts and all are clean and look like 'new'.
The only ugly part is the card pulling wheel.

   

Following the instructions I found on this forum I disassembled everything and removed the wheel and cleaned it from all the gunk that was on it.
I must say that Isopropyl alchool is not very good at removing sticky stuff.

Now I have to wait for the model shop to reopen after the 'duration' for the virus or go to the DIY shop that should still be open to get the 2 O rings to use instead of the fuel tube for model planes.

I still ave to test if the motor moves but although at home I still work most of the day :-)

Will keep you posted.
Good night
Marco

[teenix]

Hopefully then, that is the only problem :-)

cheers

Tony

(04-02-2020 09:36 PM)Vintage63 Wrote:  good evening, I opened the card reader. Checked contacts and all are clean and look like 'new'.
The only ugly part is the card pulling wheel.



Following the instructions I found on this forum I disassembled everything and removed the wheel and cleaned it from all the gunk that was on it.
I must say that Isopropyl alchool is not very good at removing sticky stuff.

Now I have to wait for the model shop to reopen after the 'duration' for the virus or go to the DIY shop that should still be open to get the 2 O rings to use instead of the fuel tube for model planes.

I still ave to test if the motor moves but although at home I still work most of the day :-)

Will keep you posted.
Good night
Marco

[aurelio]

(04-02-2020 09:44 PM)teenix Wrote:  Hopefully then, that is the only problem :-)

[BobVA]

(04-02-2020 09:36 PM)Vintage63 Wrote:  Now I have to wait for the model shop to reopen after the 'duration' for the virus or go to the DIY shop that should still be open to get the 2 O rings to use instead of the fuel tube for model planes.

If your local store doesn't have them, there's usually a seller or two on eBay with the O-rings.

[teenix]

(04-02-2020 09:36 PM)Vintage63 Wrote:  Now I have to wait for the model shop to reopen after the 'duration' for the virus or go to the DIY shop that should still be open to get the 2 O rings to use instead of the fuel tube for model planes.

I have some, I can post a couple if you want.

cheers

Tony

[Vintage63]

tested the motor this morning and it works. Used a single AAA battery. It shrieks a bit though, does it need lubricating somewhere ?

[teenix]

(04-03-2020 10:26 AM)Vintage63 Wrote:  tested the motor this morning and it works. Used a single AAA battery. It shrieks a bit though, does it need lubricating somewhere ?

The shriek is most likely worn motor bearings allowing the motor shaft to vibrate a bit when it is rotating. They are not repairable as far as I know, but it was mentioned in the Forum that a tiny amount of lubricant (grease??) placed on the worm gear end will help. This is the shaft end where it mates with the thrust ball bearing inside the plastic housing.

cheers

Tony

[Vintage63]

Good day everyone, hope you and your loved ones are doing well and keeping safe.
Some time has gone by and it is time to update you on this topic.
I'm not in a hurry and this operation takes the time that it takes :-)

Thanks to Tony the o-rings have arrvied, from Australia, and are now in place.
I have started reassembling the card reader but before closing it I did some tests.
I powered the motor with the same 1.5 battery and I've fed a card in it, the o-rings pick it up properly.

BTW - Are cards inserted from the right side ?
I recall they entered from the left but I might be mistaken because they don't !!! :-)

Fiddling with the 'clutch', or axle on which the pulling mechanism rolls, the movement of the card can either be smooth or jerky, so it comes down to having a smooth pulling movement and I need a third hand in order to be able to do this.
I now understand why the axle has a slot to insert a blade screw driver.

First MAJOR problem: the black motor cable came off from its location on the PCB.
Is there a way to solder it in place without damaging any of the circuits around it ?

Second MAJOR problem: screws.
I have taken pictures of the single parts in order to be able to put them back together but did not take pictures before removing the screws, even the pictures on this forum have all been taken with the screws removed :-(
Pictures anyone ?

Thank you and keep safe
Marco

[Vintage63]

I solved the problem I had with the black motor cable.
Both motor cables are simply inserted into female sockets and it was a simple thing to do.
I now understand why the cables are thick and don't bend so easily.

Still have to figure out where many of the screws go though :-)

Marco

[Erik-M]

There are several tutorials.
This one has large pics to show where the screws go.
https://www.keesvandersanden.nl/calculat...Geiser.php

The short small screws are the motor ones they go in first but the motor has many holes for screws and only one position is right, see pics for orientation of the wire as a reference.
The rest you can see on the pics.

I did two cardreaders, both work but from one I unfortunately damaged the label.

[Vintage63]

Hi Erik,
thank you very much for the link, I didn't have this one this document.
Now I can finsh assembling the reader.
Good night and stay safe
Marco

[Vintage63]

I reassembled the reader but not put the top back on, plugged it in and executed CATALOG 2 to get the list of commands available on the reader. By the way who has a list of them with their meaning ?

The 41 can see it but if I insert a card nothing happens.

The motot by itself works.

At one point the screen went blank and the power button did not respond.

Removed the reader and after a while the power button worked again.
Could it be that I need new batteries? Not that these ones are that old.
I recall that, 30 years ago, the first time I plugged it in it drained the batteries, not this time.

Ideas ?
THank you
Marco

[Didier Lachieze]

(04-30-2020 08:23 AM)Vintage63 Wrote:  I reassembled the reader but not put the top back on, plugged it in and executed CATALOG 2 to get the list of commands available on the reader. By the way who has a list of them with their meaning ?

There is an online manual for the card reader here.
It's part of the Greendyk site which was archived before it went offline.

[Erik-M]

Could be a battery problem, or the motor draws too much current.
See if the little dot on the axis (the head with the screwdriver slot) of the gearwheel is facing in the opposite direction of the motor.
If not use a screwdriver to turn it, it should draw less current.
In last case if its not the battery and turning the axis doesn't work, put some moly grease on the tip of the axis and a drop of sewing machine oil (check if proper for plastic) on the wormwheel.
Check also if you used the right size o-rings, I bought mine on ebay and they are fine but I heard of sellers offering the wrong size.

Maybe more experienced repairman have more ideas.

[Vintage63]

Didier, thank you for the link. I managed to find the manual in my archive as well.

Erik, the motor by itself works. I have not removed the motor from its support at all during this repair becuase I didn't deem it essential. Less parts running around is better.

I closed the card feeder enclosement and powered the motor directly before attaching it to the 41C, with a 1.5 battery, cards are dragged properly, no jamming.
I don't think it is the o-rings fault.

Cards are inserted from the right side lwith the 41C in front of you, correct?
This is what I understand from looking at the pictures in the manual.

If I select a program and go to its beginning and insert a card nothing happens.

Marco

[Erik-M]

Sometimes you need to adjust the pressure by turning the axis because the o-rings are different from the original but how did you clean the axis and install the o-rings without removing the motor ?

But if the card doesn't make the contacts work there might be some stuff from the original wheel in between. You have to open the drive slot assembly, see pics here https://www.hpmuseum.org/cgi-sys/cgiwrap...gi?read=57
Be carefull things fly out, fortunately not needed in most cases but maybe it is in your case.

[rprosperi]

Definitely try new batteries. The card reader uses a lot of current and quite often the CR will not work at all even though the 41 seems to work fine. There is no way to tell for sure until you try them, and if you will be using the CR, you definitely will be needing the extra batteries anyhow.