Test card for HP 97



#23

I'm trying to get my card reader to work after installing the O-rings on the drive wheel. The card pulls all the way through so I think the switchs are making good contact with the PCB, but I keep getting Error.

I am testing it with the only card I have with something on it, but it's one that came with the machine and I really have no idea of what's actually on it. Is it possible that the card contents can cause Error even if it reads correctly?

I think what I need is a good test card. Where can I get one?

Thanks.


#24

It finally dawned on me to enter a simple program from the User's Manual and record it. It works!

So my refurbished card reader now writes and reads. Much to my pleasant surprise, it is not at all sensitive to adjustment of the eccentric shaft. I've moved it in about 45 degree increments one way and the other and never get an Error. Only difference seems to be a minor difference in sound.

As suggested in Mike Davis' write-up I've had it it set up with the reader hanging off it's ribbon cable on the bottom side of the board throughout this testing. I'll now reassemble it properly and declare the project a success. I may put the photos I've been taking in an album and post it.


#25

Careful, Ed. It can be addictive. Now you may want to repair a second machine, just to admire its incredible power and beauty. (Gold button contacts! Big LED's!) That can lead to another..... well, never mind. Congratulations!!!


#26

A slippery slope indeed! I'll try to guard against those awful impulses. Already I'm trying to break the habit of searching eBay for HP calculators every morning.


#27

Just every morning....


#28

OK, OK, I was just trying hide my obsessive-compulsive disorder.


#29

The few who tried have died. I´m alive, though...

Edited: 5 Apr 2010, 11:19 p.m.

#30

Although the reader reads & writes fine I think it's a bit noisy. However,I don't know how noisy is too noisy, never having heard a 97 reading a card before.

Here's a movie with sound so you can hear it. It's about 1.7MB. Be sure your sound is on and truned up in Windows Media Player or whatever you use.

My card reader in action.

Comments appreciated.

If it's too noisy, how can I quiet it down?

Ed


#31

Sounds kind of noisy to me. Try putting a tiny bit of good quality grease on the worm gear, that should quiet it down. Small tubes of good quality grease can be found at most bicycle shops (although they've gotten pretty exotic and expensive these days). Lubriplate works well on this.

-Katie

Edited: 6 Apr 2010, 2:36 p.m.


#32

Thanks, Katie. I already put a couple drops of 3-in-one on the worm, but I'll try some grease. I happen to have a tube of Finish Line, which is a premium synthetic I got at a bicycle shop for another project.

#33

That does sound a little loud.

I don't remeber the uneven edge to the tone (it was almost 20 years ago that I last used an HP97) but I'm sure it was more of a hummmm than a zZzZzZzZ...

(Really hope that makes sense!)

Mike T.


#34

I agree it sounds kind of buzzy. Trying to imagine what would produce the sound. I'm a little worried that the O-rings may be a little large, although they were offered on eBay for this purpose. At one point I measured the motor current with a 1.5 volt battery source and could not get it down to the specified 180 +/- 20 mA.

Also, I'm pretty certain the tip of the eccentric shaft is properly seated since I first put it in with out the gear to see how it fit. I was very careful with the side guide springs too.

Ed

#35

ed, your card reader is not only extremely noisy, but also makes a totally "wrong" noise. if everything is working o.k., the card reader is just purring (well, sort of..).
take it apart again and check for proper alignment of worm shaft and toothwheel.

best regards,

hans


#36

I just wanted to mention something about interchange. Since Ed doesn't have someone else to exchange cards with to test his card reader he can only use self-recorded cards.

But, if he (or anyone) does exchange cards with other users then checking for interchange is important. I would think that it's not just track alignment but also the card's speed through the reader so the bpi (bits per inch) is similar to the specification. How tight is that?

It's just something I wondered about while reading this thread. I wonder if anyone still has any HP alignment cards (or if they are needed) to confirm interchange?

Gerry


#37

Interesting point. I would be willing to send a card that I have written to someone to test, and perhaps someone would do the same for me.

#38

Thanks, Hans. The alignement looks OK to me, but then I don't know how it could not be. There doesn't seem to be any way to adjust anything in that regard. I mean, the motor seems to register into place, the opposite end of the worm gear registers into an indent in the frame, and the spur gear floats with very little extra side space. What am I missing?


#39

Hello Ed,
I've saw your short movie.
It's my opinion that your reader is too much noisy, and that you must pull the card when it's out of the reader.
You have used o-rings too much wide!
BTW, have you checked the test-point on the card-reader PCA with a continuity tester? There are three test-point marked M (motor switch), F (Write protect swith) and H (head switch) on the upper left side of the PCA, that you must check with the ground signal (to the left of the three test-point) to test the switches are working properly.
Let me know.


#40

Quote:
It's my opinion that your reader is too much noisy, and that you must pull the card when it's out of the reader.


That is true. How did you know that?

Quote:
You have used o-rings too much wide!


Hadn't thought about the width, but do believe they are too large in diameter. How would width cause the noise? There is clerance enough so it's not rubbing on the sides, at least before it is assembled. Does the pinch roller force the O-rings apart? I put a drop of super glue between them.

Quote:
BTW, have you checked the test-point on the card-reader PCA with a continuity tester? There are three test-point marked M (motor switch), F (Write protect swith) and H (head switch) on the upper left side of the PCA, that you must check with the ground signal (to the left of the three test-point) to test the switches are working properly.

Just when the card is all the way in. I guess I could insert the ccard a little at a time to better test the arms individuallt.
BTW, have you nocied that one of the arms doesn't do anything at all, since its pad on the PCB is not connected to anything!

Ed


#41

Ed,


Quote:
That is true. How did you know that?

I saw it from the last frames of your short-movie.


Quote:
Hadn't thought about the width, but do believe they are too large in diameter. How would width cause the noise? .....

My mistake, it's not the width of the o-ring but the diameter. I have always purchased the o-ring from 'waterhosko'. The better.
For eliminate the noisy you should take apart the motor and apply lubricant to the tip and sides of the worm-gear. You must lubricate the thrust bearing hole too. Use moly-disulfide lubricant.

Quote:
Just when the card is all the way in. I guess I could insert the ccard a little at a time to better test the arms individuallt...

Yes, you must insert the card a little at a time to better test the arms: first the Motor switch, after the 'F' for the write protect switch and last for the 'H' magnetic head.
If the switches are all ok and again you have an error message when you try to read a card, another thing you could to test are the resistance of the two head's circuits, that should be executed with an ohmeter connected first to the wires red and yellow, and last to the wires blue and orange. You should read about the same value, from 45 to 55 Ohms for the two couples. If you read a value infinite for one of the two circuites, you have a problem on the magnetic head.
Of course, you must detach the wires from the reader's PCB to properly execute this test.
And yes, one of the arm of the switches assembly is not operative.
I hope that my contribute might help you to make progress with your card-reader.
Let me know if you make progress and I apologize for my very bad english.
Take care

Ignazio


#42

Thanks, Ignazio.

I got some model airplane fuel tubing today since it is available locally for about US$1.50 per foot. Right away I see the challenge with this approach is getting a very square cut, especially at the end that goes against the shoulder. If that end is the least bit off-square the tube will deform when it is pressed against the shoulder, setting the circumference of the roller askew and probably creating uneven pressure on the card.

Regarding the motor stopping before the card has ejected completely, is this a sign that one of the switch contacts is not working?

Ed

#43

Ignazio,

Quote:

For eliminate the noisy you should take apart the motor and apply lubricant to the tip and sides of the worm-gear. You must lubricate the thrust bearing hole too. Use moly-disulfide lubricant.


I did a Google on moly-disulfide lubricant and find that it comes in oil, grease, or dry form. Which do you use?

Ed


#44

Hi Ed,
I use grease.

Ignazio


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