Hot take: I judged a whole line of LRUs by one bad bench test and wasted a week
Pulled a comm radio off a King Air in Amarillo and the bench said fail on the first try, so I tagged the whole series for swap and told the lead we had a bad batch. Turns out my test cable had a bent pin on connector A, and the real radio passed clean once I swapped the harness out of the box. Cost me about 9 hours of pulling and reinstalling units that were all fine to begin with. Now I wiggle test the cable on my own bench before I blame the box, lesson learned the hard way. What is your go-to check before you call a unit bad?