On Friday, February 2, 2018 at 4:19:20 AM UTC-5, Phil Allison wrote:
ones that test perfect one day and go DEAD the next are not playing fair.



.... Phil

Hate it when that happens.

But it's the reason we were required to Live Dead Live in the factory where I worked, to be sure power was off before doing a repair.

Live (testing a powered circuit) proves your meter works.
Dead proves your locked out circuit is safe, provided your meter didn't die in between.
Live again proves your meter was okay.