I need some advice on cleaning/restoring tactile Space Invaders

[grodzio]

I've bought a NMB RT101+ on tactile Space Invaders recently, and the switches feel inconsistent. Some are more tactile than others, for example. I figured that they might be dirty, so I need some advice on how to clean and restore them. Is it safe to clean the contact leaves with ethanol? And how can I restore their tactility?

[Palatino]

(I don't know about cleaning them but may I ask: which converter do you use with your NMB? Sorry to hijack!)

[grodzio]

(I don't know about cleaning them but may I ask: which converter do you use with your NMB? Sorry to hijack!)

Just a DIN to PS/2 adapter. I have a PS/2 port, so that's all I need really.

[4_404]

I had some terrible condition clicky black space invaders (full of dirt and organic detritus, see pics).

IMG_20200430_204735 (1).jpg (4.72 MiB) Viewed 1236 times

I was able to clean them to a very usable condition by desoldering, disassembling, and running them through an ultrasonic cleaner for a long time. This got them to the point of functioning (originally none of them returned when pressed) but most were still pretty scratchy.

IMG_20200504_223618.jpg (4.17 MiB) Viewed 1236 times

IMG_20200504_204759.jpg (3.96 MiB) Viewed 1236 times

I ended up lubing them with 2303, and the results were pleasently surprising. I lubed the three 'rails' on the centre post, the matching parts on slider and the bottom sides of the contact arms, and the spring (as well as the track for the click follower arm on my clicky switches). I never really worked out where most of the friction came from, and I did a bunch of experiments lubing various parts of the switch, but the above method was the best feeling. The board now feels great, although due to my lack of understanding of the click machanism in these switches, I seem to have dampened the click a lot, so they sound and feel fairly different from my stock clicky board. Still, very much usable, and very happy with how it ended up.

If you're interested in lubing and my above description doesn't make sense, I can probably make some diagrams of what I did, as well as open up some of my lubed switches after 6 months or so to see what the lube has done.