HP 41 Card reader problem

[Cancuino]

Hi,

I have a card reader with some kind of failure and maybe you can help me to fix it.

When I plug it, sometimes the calculator doesn't power on and when it does it kind of freezes and the motor of the reader doesn't start.

I'm a total newbie and looking forward to your advices.

Thank you.

[Geoff Quickfall]

Software or hardware?

Software:

Easiest to fix but tedious. Try a memory rest of calculator. Then try card reader.

Hardware:

Calculator: When inserting card reader entire shell can flex. With weak screw posts or loose screws the module/battery block connection and to a lesser extent the keyboard PCA connection may become intermittent causing erroneous displays or no display. Lots written up on screw posts in the archives.

Card reader: I take it this reader has a new pinch roller (o-ring or flex tubing). May be a connection on the plug or dirt. Clean contacts on both the male (calculator) and female (card reader module.

This is like a doctor diagnosing over the phone, very iffy at best. Try the above one at a time, starting with machine reset, cleaning modules, checking screw post integrity, cleaning module/battery block contact, PCA contact and keyboard contacts and if good then tightening screws (gently).

Geoff

[Cancuino]

Hi Geoff,

I've just done the first one. Memory reset and then trying the card reader but the card doesn't move at all. I think that it could be something hardware related.

I will try the other things.

Thanks.

[Hans-Peter]

I'm the next patient doc.
My 97er reader has only "crd error". I've tried with 3 different o-rings. With all positions of the position screw, with cleaning (isoprop), check of resistance from the head wires.... No idea to bring them up. In my 41, the cards are fine. Also tested with the standard pac diag card.

Hans-Peter

[Geoff Quickfall]

Sounds like you have done this before.

I prefer the silicon tubing (military spec) with the hole in the middle. It simulates the pinch roller perfectly. The o-rings harden and I have to replace them on other people's 67 and 41s.

Using the current o-rings. I would move on to the circuit board solder joints. The card reader PCA is awkward to get to as you know. This flexes the solder joints and older brittle wires. Next the PCA to main PCA connections. Any obvious faults, do the circuits pass a simple continuity check.

I am away from home so a longer description will have to wait.

Geoff

[Geoff Quickfall]

Keep at cancuino!

[Cancuino]

(02-05-2017 09:46 PM)Geoff Quickfall Wrote:  Keep at cancuino!

I will.
I guess I should buy some o-rings, shouldn't I?.
I want to hear that tiny motor sound!!.

[Geoff Quickfall]

Look at this humorous video about repairing the 41CX card reader:

HHC card reader repair

[Cancuino]

Thank you for the video Geoff, it seems quite complicated.

[rprosperi]

(02-06-2017 01:08 AM)Cancuino Wrote:  Thank you for the video Geoff, it seems quite complicated.

The repair itself, not too bad. But doing it while entertaining the full HHC crowd can indeed be complicated. Just don't drop any small parts...

[AndiGer]

Cancuino,
Did you try the reader with another 41? Or another module inside your errorness 41? Especially in port 4, but also other ports?
Had also problems due to corrosion at the I/O block.

Did you see this thread?
http://www.hpmuseum.org/forum/thread-6626.html

Andi

[Cancuino]

I've tried another module on the 4th port and it works fine.

I have only one HP 41 and it's in a pretty good shape. With the card reader attached and the calculator off the motor doesn't move at all. If I try to turn it on, sometimes it does and sometimes doesn't. When it does it recognizes the card reader but if I list the functions in it, it usually freezes.

Best regards.

[Cancuino]

(02-05-2017 08:53 PM)Geoff Quickfall Wrote:  Software or hardware?

Software:

Easiest to fix but tedious. Try a memory rest of calculator. Then try card reader.

Hardware:

Calculator: When inserting card reader entire shell can flex. With weak screw posts or loose screws the module/battery block connection and to a lesser extent the keyboard PCA connection may become intermittent causing erroneous displays or no display. Lots written up on screw posts in the archives.

Card reader: I take it this reader has a new pinch roller (o-ring or flex tubing). May be a connection on the plug or dirt. Clean contacts on both the male (calculator) and female (card reader module.

This is like a doctor diagnosing over the phone, very iffy at best. Try the above one at a time, starting with machine reset, cleaning modules, checking screw post integrity, cleaning module/battery block contact, PCA contact and keyboard contacts and if good then tightening screws (gently).

Geoff

Hi Geoff,

could you please post some links to:
- Cleaning contacts on the card reader and the calculator (although I suspect that the calculator ones are OK).
- Checking screw post integrity.

I think that the failure must be on the card reader, since it was repaired 4 years ago.

Thanks.

[Cancuino]

I have disassembled and reassembled it according to your video.
I used 2 O-rings.

As I said before the card reader was repaired on 2013 and I noticed three things that were not like on the video:
1.- One of the metal slab had something covering it so that it can't touch the golden pins.
2.- It was really hard to take the plastic axe off. It was really hard, a lot of friction there.
3.- I couldn't remove the tiny aluminium part located on the axe of the motor.

I tested the motor and it works but when I reassembled all the pieces and plugged it to the calculator, it didn't turn on.

I could barely hear a sound just like the sound of a monitor, that kind of sound, like a sharp sound but very very low (I'm sorry, english is not my first language and it's really complicated for me to describe it).


Here are some pics of the little adventure:
https://dl.dropboxusercontent.com/u/6300...%2036.jpeg
https://dl.dropboxusercontent.com/u/6300...%2001.jpeg
https://dl.dropboxusercontent.com/u/6300...%2010.jpeg
https://dl.dropboxusercontent.com/u/6300...%2038.jpeg

I hope you can help me.

[damaltor]

I had a similar problem. When i inserted the card reader, my calculator wont turn on. It is a 41 which is in very niche shape and works nicely.

In the end, the problem was not in the card reader but in the calculator: The calculator simply will not work when anything is plugged into slot 4. The device is in perfect shape and there is nothing to be seen inside slot 4, but still it wouldnot work. The card reader works nicely with a different 41.

[Cancuino]

In my case, when I plug a module on the fourth port it works like a charm, so I think it's nothing related to the port.

Besides, the card reader doesn't work with another HP41.

Thanks for answering.

[Geoff Quickfall]

Email sent. Did you get PDF.

Geoff

[Cancuino]

Email and PDF received. Thank you Geoff.

Well, I have some news:
1.- Now I can get the calculator working with the card reader attached.
2.- When I try to read a card, the motor doesn't turn on and a high pitch noise starts.

I made two videos showing it.

CAT

Sound

I have no idea why this is happening, any help is appreciated.

Edit: I've noticed that that sound starts when the actuators of the card reader (the golden forks) touch the zone I marked on the next picture.

Contact

[Hans Brueggemann]

that sound could be a reaction of the internal DC/DC converter to an overload condition.
fortunately, the motor is "weak enough", so it is not capable of damaging the plastic gear of the drive roller. you should start from the beginning and dismantle card reader and assemble it again, but without having the drive roller assembly installed. then, insert the card and check whether the motor spins up. if you still hear the high pith whine and the motor doesn't start, the motor's rotor is probably stuck with congested lubricant, or the commutator inside the motor is somehow damaged.