buttons that don't register well

If you're having problems with the hardware of a DM42, post about them here.
Rmollov
Posts: 10
Joined: Wed May 03, 2017 5:55 pm
Location: Sydney, Australia

Re: buttons that don't register well

Post by Rmollov » Wed Apr 11, 2018 9:49 pm

My ENTER button has unacceptable behaviour - pressed close to the right edge acts like the rest of the buttons; close to the left edge - a lot quieter and weak click, and in the middle - no click at all. Registers in every case, which makes things worse, no way to tell the result unless checked in the display. I can't notice any difference in the respond when pressing both domes while calculator is disassembled. Suggestions made earlier here to play with the wide internal screws or readjusting position of the whole dome board don't look serious and reported results (fixing) - imaginary. When I opened it for the first time, the screw closer to the ENTER was laying there free, completely out of its hole, how could I fix problem by releasing it? :roll:

Michael
Site Admin
Posts: 226
Joined: Wed Apr 05, 2017 9:31 pm

Re: buttons that don't register well

Post by Michael » Thu Apr 12, 2018 11:13 am

I'm sorry for this. Finally we nailed the problem with the ENTER button.
The unequal tactile feedback is caused by the upwards bent ABS housing.
Once the calculator is taken apart and warmed up a little, it can be bent back which should solve the issue.
Please give it a try. Otherwise you can send it back to me and I'll fix it.

keithdalby
Posts: 483
Joined: Mon Apr 24, 2017 6:38 pm

Re: buttons that don't register well

Post by keithdalby » Thu Apr 12, 2018 11:16 am

Glad it's an easy fix. Would it be possible for there to be a quick video tutorial so we know what we to bend and how much please?

Rmollov
Posts: 10
Joined: Wed May 03, 2017 5:55 pm
Location: Sydney, Australia

Re: buttons that don't register well

Post by Rmollov » Thu Apr 12, 2018 1:46 pm

Thanks Michael, hope this solves the problem. I join the previous poster about video tutorial how this is to be done.
Cheers.

Michael
Site Admin
Posts: 226
Joined: Wed Apr 05, 2017 9:31 pm

Re: buttons that don't register well

Post by Michael » Thu Apr 12, 2018 2:01 pm

keithdalby wrote:
Thu Apr 12, 2018 11:16 am
Would it be possible for there to be a quick video tutorial so we know what we to bend and how much please?
I'll try making a video this weekend...

mcc
Posts: 157
Joined: Fri Jun 23, 2017 3:10 am

Re: buttons that don't register well

Post by mcc » Thu Apr 12, 2018 3:51 pm

Hi Michael,

thanks a lot for the investigation and the solution! We will ENTER an new era
of ENTERtainment (just playing with words, there is no hidden something
"between the lines" :))

A question:
When opening the back and closing the back again, there is always a certain amount
of pressure needed to close the back completly.
So I think (read: really don't know for sure), that the back a slightly to short or the
radius of the upper end of the back does not fit exactly the radius of the upper end
of its counterpart.
When "unbending"/"Stretching" (word?) the ABS part it will become a little longer.

Would this bend the ABS again after a while of usage?

Cheers!
Meino
DM 42 - SN: 00373, Firmware v.:3.7 / 3.7.1 as compiled by SwissMicros

User avatar
ijabbott
Posts: 87
Joined: Fri Dec 15, 2017 1:34 pm
Location: Manchester, UK

Re: buttons that don't register well

Post by ijabbott » Thu Apr 12, 2018 5:21 pm

I'm glad you got to the bottom of it. Did you need a fiberscope to see what was going on?

I may risk dismantling my calculator one more time to fix it once the video has been posted. We have a hot-air gun at work somewhere!

User avatar
pica
Posts: 16
Joined: Fri Mar 30, 2018 9:36 am
Location: Swaziland

Re: buttons that don't register well

Post by pica » Thu Apr 12, 2018 10:10 pm

Well, to answer my own question, when I took out the circuit board, all the little metal domes responded with a very positive click when pushed with a matchstick. This led me to think that the keyboard might be too close to the circuit board. Loosening the two big screws helped, but I am not willing to carry around a calculator with loose screws inside. The solution was therefore to put two narrow strips of photocopy paper (3mm by 40mm, folded in half longways) between the keyboard and the circuit board right at the edges of the boards and then reassemble. All the keys work just fine now.

dove
Posts: 14
Joined: Sat Mar 24, 2018 11:35 pm

Re: buttons that don't register well

Post by dove » Thu Apr 12, 2018 10:53 pm

Wow, good catch. Looking at my DM42, I suspect this bend is what I've been calling the "bulge caused by the beeper". Looking forward to the video.

toml_12953
Posts: 433
Joined: Wed May 03, 2017 5:46 pm
Location: Malone, NY USA

Re: buttons that don't register well

Post by toml_12953 » Tue Apr 17, 2018 12:38 pm

Michael wrote:
Thu Apr 12, 2018 2:01 pm
keithdalby wrote:
Thu Apr 12, 2018 11:16 am
Would it be possible for there to be a quick video tutorial so we know what we to bend and how much please?
I'll try making a video this weekend...
Did you get a video made? My Enter key is reliable only if I screw in the large-headed screws just enough to catch the threads without tightening them at all. If I tighten them even one turn, the left side of the enter key registers but there's no click. I'd like to be able to screw them all the way down and still have my keys work.
Tom L

आपका दिन शुभ हो
DM42 SN: 00025 (Beta)
SN: 00221 (Shipping)

Post Reply