Unicomp Model M not working / need advice

[feltel]

I own a Unicomp Model M build around 2012. It was stored away for quite a long time and I took it out of its storage these days for use. Unfortunately I realized that a lot of keys do not register anymore.

Through its live the keyboard lost some rivets, but not so much that this could be an issue imho. Does anyone recognize an pattern in the non working keys? Could it be the membrane?

I re-seated some of the non-working key stems but it did not help.

Bildschirmfoto_2021-12-15_09-31-39.png (68.58 KiB) Viewed 8448 times

[Muirium]

Which keys are and aren't working? Either way, that's a horrible sight!

As for the membrane matrix: I believe Unicomp still uses the same matrix as IBM. (Excepting the new Mini obviously.)

viewtopic.php?p=451764#p451764

[feltel]

The white keys do not register.

[Muirium]

Reseat the membrane connectors into the controller. If that doesn't work: prepare for a bolt mod.

[feltel]

It works, after removing and reinstalling the controller PCB. *yeah*

I consulted https://support.pckeyboard.com/knowledg ... article=71 for reference. Removing the PCB and cleaning the PCB and the membrane contacts with IPA helped indeed. But what a fragile construction this is.

[Muirium]

But what a fragile construction this is.

What are you saying, soldier? Everyone knows they're built like a tank. <mutters> Like an Italian tank.

[feltel]

*g*

Maybe the foam pad placed under the membrane dried/aged uneven. So the needed pressure which presses the membrane against the PCB contacts was not there anymore or inconsistant. Probably it would be wise to replace the foam pad with something similar.