It being the season for hacking down decorative grasses, our ancient Craftsman Hedge Trimmer woke up dead, a decade after I fixed its switch and predicted it’d be good for another decade.
After verifying the failure isn’t in the wall outlet or the extension cord, haul it to the Basement Laboratory Repair Wing, clamp the blade in the bench vise, remove a myriad screws, and pop the top:
I should have removed the screw in the extreme lower right corner and loosened the similar screw at the rear of the bottom plate; they’re two of the three machine screws engaging nuts embedded in the shell. Everything is greasy enough to let the nuts slide right out of the plastic and no harm was done, but that need not be so.
After poking around a bit and finding nothing obvious, I checked the resistance across the plug: open-circuit with the switch OFF and nearly shorted with the switch ON.
Put the case back together with just enough screws to prevent heartache & confusion, unclamp the blade, plug into the bench outlet, discover it works fine again, reinstall the rest of the screws, and continue the mission:
We moved the Praying Mantis oothecae to nearby bushes for science!