Totally out there though, have you checked the voltage at your receptacles? If the voltage is low (sometimes system grounds are not the best, and have had residential transformer start to fail), some electric motors will not start, can cause issues with brush motors too. On the flip side, a higher voltage doesn't cause as many problems. I've found lines that had a short in them, won't trip the breaker, but because the ground was bad would read 50-60vac on the hot and 30-50vac on the neutral to ground. Older power tools didn't give a crap on the voltage or lack of ground for the most part, most of the new stuff is so under engineered and sized to the bare minimum to make a profit that voltage tolerance is lower and life expectancy damn near seems half...blame it on electron flow, lol.