Dead key on 35s

[jebem]

(03-12-2016 09:07 PM)Tugdual Wrote:  Just wondering, is the 15C LE using the same technology? So far this is the best keyboard I have and now I'm worried it might follow the same path.

I would say the chinese manufacturing plants are using similar technologies for these calculators, be it a 35S or a 12C or a 15C LE.
Basically they use the same technology that Texas Instruments have patented long time ago in the 70's with one or another variant.
They use metal domes over a PCB matrix and cover the domes with a sticky plastic film.

I know that you are not willing to open your 35S, but if someone does (like myself when I'm in the mood for it), usually the key register failure common causes comes down two a couple of reasons (excluding the usual failures caused by the end users):
- The plastic key cap pin gets bent/broken/smashed even with careful usage;
- the area under the dome is contaminated with residues from the manufacturing plant.
The later cause is getting more frequent than the former, if the reports we can read here and elsewhere are to be believed (and I do believe because I have found this flaw myself).

See here this report on a HP-15C LE. For me it is a exemplar situation where quality control has space for improvement in those manufacturing plants.

And the SwissMicros recent series had the same keyboard failure caused by residues if my memory is not betraying me from what I've been reading in these forums here.
Luckily these issues with SwissMicros were promptly fixed by the owners by just following the manufacturer instructions on how to clean the contaminated domes (or else got swift replacements from SwissMicros).