My keyboard buddy Dan C. (from Wormrider and PowerLoader) had some keys fail on his beloved Alesis ION synth.

Hey was trusting enough to let me take it…

…TO THE BENCH:

Dan was kind enough to label the defunct keys before dropping it off.
Dan was kind enough to label the defunct keys before dropping it off.
after removing a set of screws on the back panel, the entire key-bed can be removed WITHOUT having to open the main (back) panel.
after removing a set of screws on the back panel, the entire key-bed can be removed WITHOUT having to open the main (back) panel.
careful with the ribbon cables that connect the banks of keys to the main printed circuit board (PCB)
careful with the ribbon cables that connect the banks of keys to the main printed circuit board (PCB)
I found a way to rest the keys in the key-bed cavity (so i didn't have to hold it up to work on). It's heavy !
I found a way to rest the keys in the key-bed cavity (so i didn’t have to hold it up to work on). It’s heavy !
These BEEFY keys have 1-springs and two switched each. I can tell that at leas the mechanics will stand up to years more of Dan's abuse.
These BEEFY keys have 1-springs and two switched each. I’m confident that at least the hardware will stand up to years more of Dan’s abuse. ┬áThese springs have to be CAREFULLY unstrung to remove any key, lest they go flying behind your bench. Note to self; buy carpet that makes it easier to find steel parts…
Finally removed the offending keys. We see the two membrane switches inside each. Each key hits one, then the other, and the key-scanner measures timing between these events to infer velocity (dynamics) of the consequent note. After a bit of contact cleaner and removing of gunk, I confirmed (with multi-meter) that each switch worked just fine.
Finally removed the offending keys. We see the two membrane switches inside each. Each key hits one, then the other, and the key-scanner measures timing between these events to infer velocity (dynamics) of the consequent note.
After a bit of contact cleaner and removing of gunk, I confirmed (with multi-meter) that each switch worked just fine.

Now we just reverse the process to re-assemble, and shoot a quite “it works” video.

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