I posted about my Fluke 1720A Programmer keyboard with scratchy Datanetics DC-60 Switches. I like the board but the scratchy switches are annoying so I wanted to see if I could disassemble and clean the switches AND get them back together in good working order. It did not appear likely to be an easy task.
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The switches are held together with two plastic rivets that have had the ends "mushroomed" to hold them in place and this prevents simply prying the switch apart.
- Original Switch
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Using a Dremel on a stand with a 3/32" bit I removed just the very end of the rivets
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- Drilled Switch
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After this it is possible to pry the switch open leaving the majority of the rivets intact for re-closing the switch.
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As others have previously noted the contacts are very similar to Hi-Tek or Stackpole. There is a bar in the slider that holds the contacts apart until the switch is depressed.
- Switch Parts
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- Switch Parts
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The riskiest part is reassembly - great care has to be taken to gently slide the bar between the contacts without bending them!
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If care is taken not to remove more than the tips of the rivets (only a millimeter or two) the rivets will snap back into place and I have found the switches to be held together firmly. They could be glued, of course, but I wanted to be able to open them again if necessary.
- Reassembled Switch
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I cleaned all the switch parts in 91% isopropanol and they are now much smoother and no longer scratchy. I did put some Superlube along the outside of the slider on one switch, but I don't really feel much difference between the lubed switch and the other newly cleaned ones - I guess it could make a difference down the road though.
Of course another issue is that desoldering, opening, cleaning and reassembling every switch on the board is quite a task. I think I'm going to just gradually work at it as time allows.
