Upgraded keypad

If you're having problems with the hardware of a DM41X or DM42, post about them here.
nephilim
Posts: 60
Joined: Sat Sep 12, 2020 10:09 pm

Re: Upgraded keypad

Post by nephilim »

Dave Britten wrote:
Sat Sep 10, 2022 7:33 pm
The keys are almost totally silent, and have a soft but very definite tactile response.
This is the description I've been waiting for to hear. Ordering mine now, too.
DM42 (free42, C47), DM15L, HP15C CE, HP35s, HP33s
redglyph
Posts: 177
Joined: Sat Dec 22, 2018 11:45 am

Re: Upgraded keypad

Post by redglyph »

I've received the new domes and placing them was relatively easy.

Unfortunately there is at least one key (SQRT) which is quite stiff and doesn't register well. Most others seem fine but it's uneven across the keyboard. The 2nd row seems somewhat stiffer and doesn't click as well as the other rows, and SQRT is really not good.

Needless to say, I'm quite unhappy, I had hope this would fix this old problem but my conclusion, after spending even more money on this, is that those keyboards are not very good.
rprosperi
Posts: 1698
Joined: Mon Apr 24, 2017 7:48 pm
Location: New York

Re: Upgraded keypad

Post by rprosperi »

redglyph wrote:
Wed Sep 14, 2022 4:34 pm
I've received the new domes and placing them was relatively easy.

Unfortunately there is at least one key (SQRT) which is quite stiff and doesn't register well. Most others seem fine but it's uneven across the keyboard. The 2nd row seems somewhat stiffer and doesn't click as well as the other rows, and SQRT is really not good.

Needless to say, I'm quite unhappy, I had hope this would fix this old problem but my conclusion, after spending even more money on this, is that those keyboards are not very good.
It's very likely the problem you are having is related to the installation. The smallest amount of dust, hair, etc. that is between the dome and the contact area can have dramatic impact on the consistency of the various buttons feeling, which sounds like is the culprit in this case. Of course no one thinks they made any mistakes during cleaning and installation, but I made just such a mistake once and had similar unhappy results.
Before dismissing this feedback, please consider all the other reports to date have confirmed it works well and as intended, and consider it may have been a simple mistake.

Please try ordering another one (this one would not be free) and go through the procedure again, being very careful to thoroughly clean the base and ensuring there is absolutely nothing trapped when you install it. If the problems persist with the new sheet, I'll personally reimburse you for the cost of the 2nd dome sheet, while if not, you'll know it was just some dirt as suggested.

Please note that this offer is for redglyph only, and is being offered specifically as an attempt to help illustrate for others what can happen during installation.
--bob p

DM42: β00071 & 00282, DM41X: β00071 & 00656, DM10L: 071/100
jch
Posts: 49
Joined: Fri Apr 28, 2017 9:11 am
Location: France

Re: Upgraded keypad

Post by jch »

DM42 Beta sn:00050 updated successfully! :D

Of course, I was quite worried about this tiny dust, floating in the air and possibly contaminating the domes or the circuit board (I don't have a cleanroom handy ;) ).
So I prepared everything for the operation, sitting quietly, avoiding sudden movements, letting the dust settle for a few minutes...
Then, still very quietly, I replaced the domes as shown in the video.
Et voilà, I now have a revived DM42 with a really nice, precise and responsive keyboard.

Thanks a lot to SwissMicros team!
jch
DM42 Beta sn:00050 / DM41X Beta sn:00016
redglyph
Posts: 177
Joined: Sat Dec 22, 2018 11:45 am

Re: Upgraded keypad

Post by redglyph »

rprosperi wrote:
Wed Sep 14, 2022 9:03 pm
It's very likely the problem you are having is related to the installation. The smallest amount of dust, hair, etc. that is between the dome and the contact area can have dramatic impact on the consistency of the various buttons feeling, which sounds like is the culprit in this case. Of course no one thinks they made any mistakes during cleaning and installation, but I made just such a mistake once and had similar unhappy results.
Before dismissing this feedback, please consider all the other reports to date have confirmed it works well and as intended, and consider it may have been a simple mistake.
I wasn't working in a manufactory "clean room" with guaranteed 100% dust-free environment but still in very clean conditions and I doubt that a speck of dust would make several contiguous domes of the same row "click" differently.

I've been extra-careful, cleaning up the surface after removing the old domes, checking that the new sheet was correctly placed before and after attaching it to the PCB. It feels fine if I push on the domes with my finger, but not when I push on the keys once reassembled. Seeing they all have different orientations, it could also simply be bad luck if the key pin presses just at the wrong position.

Of course it could be a personal mistake, usually customers shouldn't have to take products apart and do that type of operation, so while I'm working in microelectronics I'm not really assembling devices every day. I'm not complaining, I understand it's an acceptable and practical arrangement, I'm only stating the obvious risk.

The fact that 5 people reported it was working well doesn't make it infaillible, defects happen all the time in production and one couldn't even draw any conclusion from so few samples. There were many reports of DM42 working very well too, yet some customers had this keyboard problem from the start.
rprosperi wrote:
Wed Sep 14, 2022 9:03 pm
Please try ordering another one (this one would not be free) and go through the procedure again, being very careful to thoroughly clean the base and ensuring there is absolutely nothing trapped when you install it. If the problems persist with the new sheet, I'll personally reimburse you for the cost of the 2nd dome sheet, while if not, you'll know it was just some dirt as suggested.

Please note that this offer is for redglyph only, and is being offered specifically as an attempt to help illustrate for others what can happen during installation.
Thanks for the offer but I don't think you should be paying for someone else's problem. :)

It wasn't free, it's 10 CHF (plus the isopropanol) but it's not a big deal. There's a redeem code which can be used with another order, so I suppose it would be free to re-order one. I'll see later.

EDIT: apparently there were several batches and I got an early one (shipped in a simple envelope that could have been mishandled too, the post office is not that careful around here), that explains why someone reported a different foil protection sheet above. Michael kindly sent me a replacement so I'll try again in a few days.
Boub65
Posts: 231
Joined: Tue Sep 12, 2017 4:34 pm
Location: Rabat, Morocco

Re: Upgraded keypad

Post by Boub65 »

Hello,
I have a SN#00855 DM42 ordered Aug 2018 with a 2017 (c)opyright on the back.
The key registration is very soft with no clics.
The R/S key (the worst case for a calculator) registration is random.

I ordered a new foil/domes for my calculator from Swissmicros.

As for Michael's customer service... what I can tell from my personnal experience is that it is top notch!
I received since my first order in 2017 : 1 DM41L faceplate and 1 DM15L LCD screen in no time with no questions asked and no fees

I will tell you how DM42 the foil/domes replacement goes.
Last edited by Boub65 on Sun Sep 18, 2022 3:38 pm, edited 2 times in total.
Sincèrement, Sincerely, 73,
Boubker

DM15L, DM41L, DM42 #00855 (domes upgraded), DM41X #00707
HP48SX (with dark screen), HP42s, HP32SII (1990 with fraction bug), HP41C/CV
TI-89 titanium, CASIO fx-cg50 and Numworks (to play with micropython)
User avatar
48GX
Posts: 180
Joined: Wed May 20, 2020 4:37 am

Re: Upgraded keypad

Post by 48GX »

I just ordered new foil/domes for two of my older DM42 units. Can someone recommend a cleaner to use? An amazon link would be awesome. I have seen "MG Chemicals NuTrol" mentioned, but I am not a hardware guy and want to do this correct the first time. TIA
Waiting for SM to release DM42 hardware with one additional row of keys.
DM42, DB48X, DM32, HP42s, DM41X, HP35s, DM41L
Raising a next generation RPN/RPL user.
rprosperi
Posts: 1698
Joined: Mon Apr 24, 2017 7:48 pm
Location: New York

Re: Upgraded keypad

Post by rprosperi »

Isopropyl alcohol (90+%) will work best (do not use "rubbing alcohol" intended for use on skin), unless there is unusual amounts of adhesive residue from the original foil. If so, clean first with a "Goo-Gone" type of cleaner which is designed to be a solvent for any/all kinds of adhesives, and then once visually clean, repeat the cleaning with the alcohol.

https://www.amazon.com/Amazon-Brand-Iso ... B07NFSFBXQ

and

https://www.amazon.com/MAGIC-GGSL2-12-H ... B000LLUNW8
--bob p

DM42: β00071 & 00282, DM41X: β00071 & 00656, DM10L: 071/100
redglyph
Posts: 177
Joined: Sat Dec 22, 2018 11:45 am

Re: Upgraded keypad

Post by redglyph »

Boub65 wrote:
Sun Sep 18, 2022 2:48 pm
As for Michael's customer service... what I can tell from my personnal experience is that it is top notch!
I received since my first order in 2017 : 1 DM41L faceplate and 1 DM15L LCD screen in no time with no questions asked and no fees

I will tell you how DM42 the foil/domes replacement goes.
Yes, he's always been quite receptive and very helpful.

There was a period during which I got no reply as started worrying but it must have been a couple of weeks off and the usual busy period just before it. Now it's back to normal. I was also unlucky to get early batches of the new dome sheets (after buying the DM42 in early stage a few years ago). Nothing out of the ordinary for a small production I think. In conclusion, I'll be more patient next time and wait until everything had time to be ironed out. :)
EM41
Posts: 192
Joined: Mon Mar 30, 2020 12:10 am
Location: Overijssel Netherlands

Re: Upgraded keypad

Post by EM41 »

redglyph wrote:
Mon Sep 19, 2022 9:37 am
In conclusion, I'll be more patient next time and wait until everything had time to be ironed out. :)
Whats the fun of that, I had the best time of my life betatesting the DM41 with bugs, errors, keys leaving paint etc :D
HP41C (2x), HP41CV, HP41CX, DM41X β, DM41X, DM42, HP11C, HP48G, HP97
Post Reply