Got my hands on a too cheap to let it pass #op-z. It had faulty buttons.
Opening it and cleaning with isopropyl alcohol did not work well enough.
Very carefully tinning the corroded copper tracks seems to have worked much better.
The worst part is putting the keyboard back together, with that horrible sticker. Not cool, #TeenageEngineering :(
Trying to do some #timeproofing against #plannedobsolescence