DM 15L keypress problems

[rflesch]

In another thread, Bernd Grubert wrote:

"When I use the DM-15L (new version with metal domes) I sometimes (~every 10th to 20th) loose a keypress. The lost keypresses usually happens when I type fast. They cannot be reproduced and are not specific to certain keys. When I type slowly everything seems to be ok."
(...)
"Has anyone else observed keyboard problems with the DM-15L, too?"

I believe this is worth a thread of its own.

I have the ***exact same problem*** with my DM-15L (S/N# 00205). The calculator was delivered with the original board, which was then replaced by SwissMicros with the metal dome board. Both boards have the *same* problem, i.e. keypresses are lost at random, as Herr Grubert reports.

I would love to recommend the DM15L to other RPN fanatics - but I can't because the calculator is unusable for everyday work under these circumstances. I have to check each and every keypress while doing a quick calculation.

I have carefully removed a portion of the sticky tape with the domes from the board, but I did not find any dust, debris, stain etc. underneath. I am afraid that this is NOT a *keyboard* hardware problem. I believe that the processor simply does not accept key-press events at certain points in time. However I was unable to find any reproducible periodicity.

I had even considered to purchase another one because of the keyboard problem, thinking my 15L might be a "lemon", but of course I won't do this, considering the reports of Mr. Grubert.

It's sad because otherwise the DM-15L calculator is a pipe dream come true.

Regards
Roman