Model M key issues:

[Green Maned Lion]

I have a pair of Battleships, one of which I use in my van, and the other in my home office. Type Is; the one in my van is a 1985; the one in my office is a 1988. The one in my van was modded by ClickyKeyboards, including replacing the left splitshift and tilda keys with an ANSI left shift that came out of ClickyKeyboards stash.

A few weeks ago on the one in my van, the right shift key suddenly started binding when pressed on the right of the key. I made a note to swap out that key with another at some point, never got around to it.

Today, the left key started quite suddenly clacking like a keyboard with bad rivets; key rim on barrel plate. It was fine, and then clack every time. When I got home, I pulled one of each key off one of my many Model Ms I don't use; this happened to be a 1391401 that I had swapped a Unicomp New Model M Mac set onto (and put its set on a New Model M Mac), so these were barely used Unicomp keys. I was fairly confident that swapping the binding key would fix the problem... and I was correct. I was also fairly confident that swapping the clacking key would not solve the problem... and I was wrong. Solved it completely.

I went back in to my office, and placed the suspect keys on the 1391401. The right shift key bound on that, too, albeit not as badly, and the left shift key clacked just as bad. I have placed an order for new keys from Unicomp (I wanted to colourise them to match the rest of the custom Unicomp sets on those boards, anyway), so I think its a done problem for now, granting that running a 40 year old board in a rough environment is not for those who don't want to tinker.

But what I'm wondering is... why did these keys suddenly start behaving in these ways?

[Falkenroth]

Guessing maybe heat? Does the interior of the van get warm in the summer months? I live in Arizona and temperatures could deform plastic. I have had a few keys that were never right from new. Some defect on the key that would cause issues. Normally after I get a set of keys to work with a board I'm good after that. Installing a new set of keys on a board can be a pain once in a while when a key or two doesn't work like it should. I have ran into this problem myself installing replacement keys. It's rare but does happen from time to time.

[Green Maned Lion]

Yeah, it definitely gets hot, but not insanely so. When the van is not in use as an office, or being driven (and thus with climate control) its is parked, typically in my driveway, with the rear of the van facing west- but the rear windows are all heavily tinted, and the back of the van is heavily insulated with some Thinsulate SM900L and mostly Havelock wool- I did that work myself. The highest temperature I observed in direct sunlight on the van is 108°F, granting this is measured by a thermometer that is magnetically attached to the sidewall of the van, so its partially measuring the metal its on. But the board is always covered by a white towel when not in use, so its not getting a greenhouse magnification, and the window area thats next to is mostly blocked from it by the 34" UW monitor. But the key getting warped might explain it- but why just the shift keys?

[Falkenroth]

Normally if there is key to give me a problem its the large shift key then followed by the enter key above it. Alignment issues. Probably more common with later Lexmark and Unicomp keys. Who knows maybe IBM keys had their issues also but had better quality control and never left the plant.