Hi-Tek Series 725 Disassembly Is Somewhat Tedious

[smarmar]

I was using my Hi-Tek Series 725 for a few years until some of the keys became difficult to register, and all the keys seemed to require different amounts of torque to register the keystroke. So, I decided to dig it out of the drawer and disassemble it. What a unique, weird-looking piece of equipment this is. After cleaning it I'm thinking of lubing the linear shafts

For those who aren't familiar with the "space invader" switch: The small contact prongs are quite fragile and can be easily bent, and the tip of one of the two prongs in each switch is divided into three tiny fingers. I found one that had previously been bent. It takes quite a bit of torque to pull the space invaders off of the board. I had to brace the board with my fingers so the tiny springs under the switches wouldn't go flying as the switch was pulled off (which they did anyway). But my fingers had to be strategically placed so I didn't touch any of the surrounding contacts—challenging.

The large Enter key has two wiry stabilizers under its hood, something I wasn't expecting.
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[fohat.digs]

When you de-solder the switches you will discover that the thin wire pins also lack strain relief.

[smarmar]

I don't intend to desolder any switches unless that what it takes to replace the metal contacts. I'm not comfortable soldering anything beyond speaker wire and I have no experience at desoldering.

I cleaned all of the contacts with Deoxit D5 by soaking the corner of a business card and vigorously sliding it between the metal bits. I bent one of them, though, by reseating its key over it at an angle. It was the F1 key, so not a huge loss. Magically, the bent switch in the photo now works and other previously troubled keys are now working perfectly. I also lubed the stabs and key shafts and they feel nice and buttery now. Previously, the keys varied in finger pressure and some felt gritty, but now they're all relatively consistent.

Overall, I'm quite satisfied with the results.