Finally an HP-41CV owner - Printable Version

Finally an HP-41CV owner - Printable Version

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Finally an HP-41CV owner - Xorand - 07-27-2021 04:58 AM

I've been going back and forth on picking up a 41-CV or 41-CX. They've typically always been a bit rich for my blood, especially the CXs. Finally ran across a good deal on a very gently used CV and picked it up. It arrived today and I'm super pleased with it.

Date code puts it at 13th week of 1982, made in Singapore. It is a fullnut. All keys work great, display is clear, all battery and module contacts are clean as new. It came with the original box (corners taped up), two manuals, and case (with foam padding). Only thing missing is the side cover. Just ordered one on eBay.

This calculator joins my 48G and 28S. Let the programming begin!

[Image: i-VSvrGdB-L.jpg]

RE: Finally an HP-41CV owner - BillBee - 07-27-2021 10:44 AM

Congrats! I know how you feel as I did the same last year and picked up my first 41 as well. It really is a great machine simple on the surface and can get as complicated as one desires. The only regret I had was realizing I should have got one decades ago. Smile

-Bill

RE: Finally an HP-41CV owner - Sylvain Cote - 07-27-2021 11:04 AM

Congratulation, a very nice package indeed! Smile

Just a small warning though, from the second picture, it looks like you have bottom case broken posts.
This is an often seen problems with the HP-41 and there are several solutions for it:

Sylvain

RE: Finally an HP-41CV owner - Xorand - 07-27-2021 04:13 PM

(07-27-2021 11:04 AM)Sylvain Cote Wrote: Just a small warning though, from the second picture, it looks like you have bottom case broken posts.

If you are referring to the curve of the case, that is due to the lens on my phone camera. The calculator sits flat and doesn't have any apparent flex in that area, nor have I noticed any operating anomalies consistent with the broken post/zebra connector issue.

I definitely will keep an eye out for that, though, as I realize regardless of light use or great care of the machine brittle plastic is a guarantee. This was definitely in the back of my mind when deciding to purchase a fullnut version machine.

RE: Finally an HP-41CV owner - JurgenRo - 07-27-2021 06:12 PM

(07-27-2021 11:04 AM)Sylvain Cote Wrote: Congratulation, a very nice package indeed!

Just a small warning though, from the second picture, it looks like you have bottom case broken posts.

Sylvain

How did you figure that defect from the second picture, Sylvain? Undecided

Edit:
... ok, Xorand explained it indirectly, I suspect?

RE: Finally an HP-41CV owner - dmh - 07-28-2021 12:16 AM

It looks like there is a gap between case halves on the lower left corner in the second photo.

This is exactly how my broken post 41cv looked.

Might be the photo though.

(07-27-2021 04:13 PM)Xorand Wrote:
(07-27-2021 11:04 AM)Sylvain Cote Wrote: Just a small warning though, from the second picture, it looks like you have bottom case broken posts.

If you are referring to the curve of the case, that is due to the lens on my phone camera. The calculator sits flat and doesn't have any apparent flex in that area, nor have I noticed any operating anomalies consistent with the broken post/zebra connector issue.

I definitely will keep an eye out for that, though, as I realize regardless of light use or great care of the machine brittle plastic is a guarantee. This was definitely in the back of my mind when deciding to purchase a fullnut version machine.

RE: Finally an HP-41CV owner - Sylvain Cote - 07-28-2021 12:57 AM

(07-27-2021 06:12 PM)JurgenRo Wrote: How did you figure that defect from the second picture, Sylvain?

(07-27-2021 04:13 PM)Xorand Wrote: If you are referring to the curve of the case, that is due to the lens on my phone camera.

(07-28-2021 12:16 AM)dmh Wrote: It looks like there is a gap between case halves on the lower left corner in the second photo.

Exactly, the top-half-case + filler + bottom-half-case should not have space between them and here it looks like there is.
I have my doubts, but as Xorand and dmh said, it could be how the picture was taken.

Sylvain

RE: Finally an HP-41CV owner - Xorand - 07-28-2021 07:32 AM

Well, looks like you are correct. Just took the calculator out of the case to inspect the case half alignment and it does have some flex/gaps. Also, now the calculator won't turn on. Sigh.

Guess it's on to fixing the issue.

RE: Finally an HP-41CV owner - Steve Simpkin - 07-28-2021 09:59 AM

(07-28-2021 07:32 AM)Xorand Wrote: Well, looks like you are correct. Just took the calculator out of the case to inspect the case half alignment and it does have some flex/gaps. Also, now the calculator won't turn on. Sigh.

Guess it's on to fixing the issue.

Try turning it on while pressing the top and bottom halves together. That is often another verification that the posts are broken.

RE: Finally an HP-41CV owner - rprosperi - 07-28-2021 12:19 PM

(07-28-2021 09:59 AM)Steve Simpkin Wrote: Try turning it on while pressing the top and bottom halves together. That is often another verification that the posts are broken.

An easy way to try Steve's advice:

1. Put the 41 on a table

2. Press firmly on the left (near the "X") and right (near the "3") outer edges with one hand

3. While holding these down, press [ON] with the other hand

It will likely power-on and if so, this confirms it's a post repair job.

RE: Finally an HP-41CV owner - Xorand - 07-28-2021 03:45 PM

I've taken it apart and verified the posts have failed. As a matter of fact, a previous owner attempted a fix it (that apparently worked for a little while).

I'm looking at options moving forward. Repair efforts will be hampered a bit due to the fact I'm currently traveling in my RV away from home where most of my tools are and a convenient place to have parts mailed to.

I'll probably re-address this in early September when I'm back home. For now, it's packed away in its box.

Thanks for all the tips and links.

RE: Finally an HP-41CV owner - BillBee - 07-28-2021 04:19 PM

If you are on the road and can find a hardware store you might be able to just source a couple of screws. IIRC #2 machine head 3/8" - should get you in the ballpark.

The longer screws go through the broken posts and sink into the screw holes in the base.

Save Travels!
Bill

RE: Finally an HP-41CV owner - Xorand - 07-28-2021 09:09 PM

(07-28-2021 04:19 PM)BillBee Wrote: If you are on the road and can find a hardware store you might be able to just source a couple of screws. IIRC #2 machine head 3/8" - should get you in the ballpark.

The longer screws go through the broken posts and sink into the screw holes in the base.

Save Travels!
Bill

This post prompted my inner McGyver to come out. Though I'm away from home and most of my electronics/tools, I do have a toolbox full of tools and spare parts for my RC car hobby with me.

In there, I found a couple plastic collars just the right length to suffice as the required standoffs in place of the now-removed broken posts. They were a little too big around, but running them on a piece of 320 grit sandpaper brought them down to appropriate diameter.

I drilled the old posts down just to below the surface level of the keyboard circuit board and carefully glued the new standoffs to the tops of the old posts, leaving the center hole clear. I reassembled everything with a couple longer screws I found in my RC parts bin that are just right for grabbing into the remaining lower posts and clamping everything together firmly.

And.....

[Image: i-pj3xPVm-L.jpg]

I'm happy for now. One tradeoff I had to make is that the screws I found have a sort of washer-like flat surface just below the head. This won't sink all the way down into the holes on the back, so I cut one of the rubber feet in half and put a half-foot on each of the lower squares.

[Image: i-drL7RKV-L.jpg]

I'll eventually get proper sized screws with smaller heads and pick up some replacement rubber feet to get it back to original shape. But, for now, I'm happy it is working again.

RE: Finally an HP-41CV owner - dmh - 07-28-2021 11:29 PM

Nice :-)

What type of glue did you use?

RE: Finally an HP-41CV owner - Xorand - 07-29-2021 01:11 AM

(07-28-2021 11:29 PM)dmh Wrote: Nice :-)

What type of glue did you use?

I know it's not preferred, but Super Glue gel. Just a tiny dab to hold the new spacers straight during assembly since the screw passes through to the existing case posts.

I wanted to make the fix only semi-permanent since I'll probably re-do the whole thing in a month or so when I'm home and can use something more appropriate - both hardware- and adhesive-wise.

RE: Finally an HP-41CV owner - BillBee - 07-29-2021 11:03 AM

(07-29-2021 01:11 AM)Xorand Wrote:
(07-28-2021 11:29 PM)dmh Wrote: Nice :-)

What type of glue did you use?

I know it's not preferred, but Super Glue gel. Just a tiny dab to hold the new spacers straight during assembly since the screw passes through to the existing case posts.

I wanted to make the fix only semi-permanent since I'll probably re-do the whole thing in a month or so when I'm home and can use something more appropriate - both hardware- and adhesive-wise.

Congrats! If you have the old feet - double sided Scotch tape does a really good job. TBH If the fix works I would leave it be. The longer screws should hold nice and tight. On the other hand I do understand the need to tinker. Smile

-Bill