Maintenance/Mouse button replacement: Difference between revisions
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== Background and problem == | == Background and problem == | ||
I'm your ordinary sort of office worker, who types and clicks far too often in the course of a day. Various body parts connected to these devices are getting old and very much appreciate that my employer has supplied me with a mid-range ergonomic keyboard and mouse. Office workers of the world, you are advised to ask for at least this much. I think I'm emotionally attached, perhaps it makes me feel fancy that someone spent one hundred euro on me, or one must perform one's longevity once the job becomes a career, like a delivery driver hanging a pair of fuzzy dice over the rear-view mirror after pulling away from headquarters. | I'm your ordinary sort of office worker, who types and clicks far too often in the course of a day. Various body parts connected to these devices are getting old and very much appreciate that my employer has supplied me with a mid-range ergonomic keyboard and mouse. Office workers of the world, you are advised to ask for at least this much. I think I'm emotionally attached, perhaps it makes me feel fancy that someone spent one hundred euro on me, or one must perform one's longevity once the job becomes a career, like a delivery driver hanging a pair of fuzzy dice over the rear-view mirror after pulling away from headquarters. | ||
The mouse trouble began when I moved into a "home office"—we'll spare most of the details except to say that my standing desk is not much more than a cutting board screwed to the wall at navel height. This is the perfect height for extremely destructive impact of any plastic-encased electronics unlucky enough to fall to the floor, and small enough that this happens often. My mouse has suffered and its once-noble exterior is held together either by gravity or by a small number of the original fasteners. But it still clicks! | The mouse trouble began when I moved into a "home office"—we'll spare most of the details except to say that my standing desk is not much more than a cutting board screwed to the wall at navel height. This is the perfect height for extremely destructive impact of any plastic-encased electronics unlucky enough to fall to the floor, and small enough that this happens often. My mouse has suffered and its once-noble exterior is held together either by gravity or by a small number of the original fasteners. But it still clicks! | ||
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== What could possibly go wrong? == | == What could possibly go wrong? == | ||
To | To lift both legs on one side, I think the right tool would be a hot air setup or a double-headed iron. Desoldering the legs one at a time is hard to do otherwise. I relied on the versatile thumbtack to apply some pressure to the joint as I heated up each pad in turn. | ||
In hindsight, I relearned the lesson that coffee and fine motor work mix poorly. My hands were trembling like leaves and I probably used ten times the force that I should have when pushing the thumbtack under the switch. I also should have pried only at the legs and not at the body of the switch itself. | In hindsight, I relearned the lesson that coffee and fine motor work mix poorly. My hands were trembling like leaves and I probably used ten times the force that I should have when pushing the thumbtack under the switch. I also should have pried only at the legs and not at the body of the switch itself. | ||
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Here are some photos of the damage: | Here are some photos of the damage: | ||
[[File: | [[File:Old_and_torn_microswitches.jpg|left|thumb|Removing the original microswitches has wounded their host]] | ||
[[File: | [[File:Mouse_switch_board_with_missing_traces.jpg|thumb|There should be no brown visible, this shows that electrical traces were torn away.]] | ||
It's a bit like discovering that | It's a bit like discovering that bits of a placenta are missing after birth: this is going to be a serious problem and we shouldn't continue without knowing exactly what went wrong. | ||
[[File: | [[File:Microswitch_internal_circuit.png|thumb|Internal schematic for a microswitch]] | ||
Nonetheless, I thought I would | Nonetheless, I thought I would try to finish the replacement as planned. | ||
After all, the internal wiring for these switches has the left and right pads tied together internally so it's possible that we only need one pad conducting the signal and the other would have no traces, purely for mechanical attachment. This could also explain why the exact same pads tore more easily on each switch? | |||
The new switches went in. | |||
I should mention at this point that I'm a complete hack—an unlicensed hobbyist. I was let go from a summer job soldering for a hardware video artist decades ago, and flashbacks from this experience came against my will, singeing my conscience with a cloud of lead smoke even at this distance through time, as I sweat over two small switches. | |||
Okay but it went uneventfully and here is the result | Okay but it went uneventfully and here is the result, notice the handsome slate-gray nubs. | ||
[[File:Mouse with new microswitches.jpg | [[File:Mouse with new microswitches.jpg|thumb|New mouse same as the old mouse|left]] | ||
There was a slight height difference between the old and new switches, so I was ready to sand down the part of the button which does the internal pressing. | There was a slight height difference between the old and new switches, so I was ready to sand down the part of the button which does the internal pressing. | ||
[[File:Two types of microswitch.jpg | [[File:Two types of microswitch.jpg|thumb|Side view of old (left) and new (right) switches]]However, this is where the story turns sad: although the mechanical clickiness feels better than what I remember of original condition, there is no signal sent from either button. They are dead to the computer, and a multimeter confirms nothing is happening on the board. | ||
My photographer suddenly gets distracted by the pretty trees outside of our window and mercifully snaps a few photos of that, instead of zooming in on my shed tears as a more seasoned journalist might have done.[[File:Trees outside a window.jpg|thumb|All is not lost.|left]] | |||
== Nothing to lose but our chains == | |||
[[File: | [[File:Scattered screws.jpg|thumb|So many screws]] | ||
Time to go deep. Take the everything apart and find out what's going on. I'd rather not pull the switches back off, for fear of tearing out the remaining traces. Instead, there's got to be a way of reconnecting the signals that connected to the missing surface-mount pads. A continuity tester confirms that the working buttons do what we might expect: one side has a positive voltage and the other causes a wire in the board connector jumper to toggle between high-impedance and the positive voltage. The broken buttons don't cause a similar signal anywhere on the jumper, and it's hard to tell where the traces should have gone because of the high-obscurity board layout and black solder mask. | |||
== Notes == | == Notes == | ||