buttons that don't register well

If you're having problems with the hardware of a DM41X or DM42, post about them here.
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Walter
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Re: buttons that don't register well

Post by Walter »

IMHO the truth is in between: issues concerning keyboard electromechanics are certainly not the rule, but the rate seems to be higher than what I'd call 'exceptions'. Exact figures may be known by SM, at least they should. As Lance (i.e. lkraven) wrote, some of these issues may be caused by small batch production techniques and methods applied but I don't know enough about them.

If the landscape model (DMxxL) keyboards really didn't show the issues reported for the DM42 (this must be verified, however) then this observation would be a first pointer to the root cause. Depending on the production flow and methods, each DM42 may contain up to 43 samples for testing hypotheses about the causes for those issues.
WP43 SN00000, 34S, and 31S for obvious reasons; HP-35, 45, ..., 35S, 15CE, DM16L S/N# 00093, DM42β SN:00041
fcrvincent
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Re: buttons that don't register well

Post by fcrvincent »

Keyboard issues on the DM1xL seem to be indeed less frequently reported but do occur still (plus I believe that only a few people report issues so what we see on the net is probably just the 'tip of the iceberg'). As recently as 11 Jan 2018 one Amazon (verified) reviewer of the DM15L said : "...The keys on the HP version have a great feel and doesn't need much press force. This calculator needs more force to push the keys... I found that if you press the keys too fast, the numbers won't register which leads to mistakes in my calculations. I have to slow down and recheck everything I do..."

The issue seems to be that the keys tactile response does not match with the domes clicks in some cases. Production variations could be an issue and I was thinking that the design of both the DM1xL and DM42 should be improved (easier said than done obviously!) to allow for larger tolerances at production.

For example may be the keys should bend more softly and/or the domes should be more flexible and may be the keys on the DM42 should be flat like on the DM1xL (they seem to be slightly slanted on the the DM42).

Not sure but the keyboard design is very similar to that of HP calculators I understood and there should only be small corrections for the DM1XL and DM42 to be perfect.
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Re: buttons that don't register well

Post by H2X »

fcrvincent wrote:
Sun Jan 27, 2019 11:54 am
Keyboard issues on the DM1xL seem to be indeed less frequently reported but do occur still (plus I believe that only a few people report issues so what we see on the net is probably just the 'tip of the iceberg'). As recently as 11 Jan 2018 one Amazon (verified) reviewer of the DM15L said : "...The keys on the HP version have a great feel and doesn't need much press force. This calculator needs more force to push the keys... I found that if you press the keys too fast, the numbers won't register which leads to mistakes in my calculations. I have to slow down and recheck everything I do..."

The issue seems to be that the keys tactile response does not match with the domes clicks in some cases. Production variations could be an issue and I was thinking that the design of both the DM1xL and DM42 should be improved (easier said than done obviously!) to allow for larger tolerances at production.

For example may be the keys should bend more softly and/or the domes should be more flexible and may be the keys on the DM42 should be flat like on the DM1xL (they seem to be slightly slanted on the the DM42).

Not sure but the keyboard design is very similar to that of HP calculators I understood and there should only be small corrections for the DM1XL and DM42 to be perfect.
My DM42's keyboard is really very good now, after replacing the domes and bending the keys slightly back and forth as suggested somewhere on this forum.

My HP41CX and HP15C LE feel ever so slightly different, but I have no longer any complaints with my DM42.
What is the metric tensor in imperial units?
fcrvincent
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Re: buttons that don't register well

Post by fcrvincent »

Another reviewer on Amazon had the keyboard issue (20 Jan 2019): "20 January 2019 - Published on Amazon.com Verified Purchase. "..I too had some keyboard issues. Michael at Swiss Micros helped me out. It took some time and some patience.."

The keyboard issue, at least on the DM42, seems to be endemic and for now and although it is a very nice device I probably won't risk it. Also one can wonder if those keyboard fixes proposed will be as durable as the rest of the hardware seems to be.

I may try the DM15L that seems less prone to this issue.
jaykstone
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Re: buttons that don't register well

Post by jaykstone »

Has anyone tried replacing the dome switches?
I purchased a DM42 and received it last weekend. I immediately loved everything about it except the keys. Keys were hard to press, and many of them could click without registering unless i pressed harder after the click. I decided I was intent on keeping this calculator and really did not want to send it back.
First I tried the gentile key bending. this did reduce the required force, but keys could still click and not register. Next I put a dab of UV curable plastic on center of each dome. this helped on some keys, but was too thick on others. I gently ground down the added plastic until all keys worked. This was better than when I started, but I would still miss some keystrokes where a click was felt but the press did not register.
I took the DM42 to work for a day and decided the keyboard was just causing too many mistakes.
I peeled back the sheet of domes, and everything looked perfectly clean. I cleaned with Isopropyl alcohol anyway, and still no change.

Finally I decided to remove the plastic I had added on and replace the snap domes. first I peeled off the plastic bits I had added with tweezers. The only domes I had on hand was some 6mm domes I was able to salvage from some scrap keypads at work, but it looked like they might work even though they are smaller. I carefully removed half of the original 8mm domes (from top half of keyboard)and replaced them with the domes I had on hand, carefully centering each one and sticking it on the plastic sheet. Upon re-assembly, all of the keys with the new domes worked perfectly. I could not get a key to click without registering. I repeated this on the remaining keys with the same result. Now every key works great.

Has anyone else tried this? I suspect there may be other domes (from Snaptron etc) to consider from a feel perspective, but based on my results it seems like replacing the domes could be promising. Any thoughts?

Jay
Logan
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Re: buttons that don't register well

Post by Logan »

My only thought is that's awesome. I've never done anything like replacing domes and would love to try or see a video on it. Glad it works.
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H2X
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Re: buttons that don't register well

Post by H2X »

jaykstone wrote:
Wed Sep 25, 2019 5:14 pm
Has anyone tried replacing the dome switches?
I purchased a DM42 and received it last weekend. I immediately loved everything about it except the keys. Keys were hard to press, and many of them could click without registering unless i pressed harder after the click. I decided I was intent on keeping this calculator and really did not want to send it back.
First I tried the gentile key bending. this did reduce the required force, but keys could still click and not register. Next I put a dab of UV curable plastic on center of each dome. this helped on some keys, but was too thick on others. I gently ground down the added plastic until all keys worked. This was better than when I started, but I would still miss some keystrokes where a click was felt but the press did not register.
I took the DM42 to work for a day and decided the keyboard was just causing too many mistakes.
I peeled back the sheet of domes, and everything looked perfectly clean. I cleaned with Isopropyl alcohol anyway, and still no change.

Finally I decided to remove the plastic I had added on and replace the snap domes. first I peeled off the plastic bits I had added with tweezers. The only domes I had on hand was some 6mm domes I was able to salvage from some scrap keypads at work, but it looked like they might work even though they are smaller. I carefully removed half of the original 8mm domes (from top half of keyboard)and replaced them with the domes I had on hand, carefully centering each one and sticking it on the plastic sheet. Upon re-assembly, all of the keys with the new domes worked perfectly. I could not get a key to click without registering. I repeated this on the remaining keys with the same result. Now every key works great.

Has anyone else tried this? I suspect there may be other domes (from Snaptron etc) to consider from a feel perspective, but based on my results it seems like replacing the domes could be promising. Any thoughts?

Jay
I have, and it worked fine - I am now super happy with my DM42. It is an early beta - I am a bit surprised that the problem isn't solved yet. What is your S/N?
What is the metric tensor in imperial units?
jaykstone
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Re: buttons that don't register well

Post by jaykstone »

Mine is new (I think) S/N 03976.
Jay
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inautilus
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Re: buttons that don't register well

Post by inautilus »

S/N 03976. Wow.

DM42 issues ... still persist. I've been holding back on purchasing at least 2 DM42s (one for me, and one for my enthusiastic, tech minded 16 year old) until I was confident that those pesky keyboard issues had finally been resolved. So, you can imagine how deflated I felt when I read the following post:
jaykstone wrote:
Wed Sep 25, 2019 5:14 pm
Has anyone tried replacing the dome switches?
I purchased a DM42 and received it last weekend. I immediately loved everything about it except the keys. Keys were hard to press, and many of them could click without registering unless i pressed harder after the click. I decided I was intent on keeping this calculator and really did not want to send it back.
First I tried the gentile key bending. this did reduce the required force, but keys could still click and not register. Next I put a dab of UV curable plastic on center of each dome. this helped on some keys, but was too thick on others. I gently ground down the added plastic until all keys worked. This was better than when I started, but I would still miss some keystrokes where a click was felt but the press did not register.
I took the DM42 to work for a day and decided the keyboard was just causing too many mistakes.
I peeled back the sheet of domes, and everything looked perfectly clean. I cleaned with Isopropyl alcohol anyway, and still no change.

Finally I decided to remove the plastic I had added on and replace the snap domes. first I peeled off the plastic bits I had added with tweezers. The only domes I had on hand was some 6mm domes I was able to salvage from some scrap keypads at work, but it looked like they might work even though they are smaller. I carefully removed half of the original 8mm domes (from top half of keyboard)and replaced them with the domes I had on hand, carefully centering each one and sticking it on the plastic sheet. Upon re-assembly, all of the keys with the new domes worked perfectly. I could not get a key to click without registering. I repeated this on the remaining keys with the same result. Now every key works great.

Has anyone else tried this? I suspect there may be other domes (from Snaptron etc) to consider from a feel perspective, but based on my results it seems like replacing the domes could be promising. Any thoughts?

Jay

Is this ever going to be resolved ...?

PS ... makes one wonder how many others out there (world-wide) are also reluctantly sitting on their money, really wanting to purchase, but ...
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jaykstone
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Re: buttons that don't register well

Post by jaykstone »

"DM42 issues ... still persist. I've been holding back on purchasing at least 2 DM42s (one for me, and one for my enthusiastic, tech minded 16 year old) until I was confident that those pesky keyboard issues had finally: been resolved. So, you can imagine how deflated I felt when I read the following post:..."



To be fair, I am quite particular about calculator keys. It is entirely possible the may people would have been okay with my DM42 the way it was when I got it. After changing out the domes I am now completely happy with it. I would now put my DM42 keyboard on par with any of my HP calcs. The feel is a little firmer and more "clicky", but now seems to be 100% reliable. I certainly don't want to deter anyone from purchasing the DM42. I just felt that the keys could have been better and wanted to see if my experience with canging out the domes was typical or possibly encourage anyone who is not fully satisfied to try changing the domes.
I fully understand your hesitation to buy. I have waited over a year to purchase for the same reason, but at this point I am very happy with the purchase and glad I made it.
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