For those of you that know me, I have a swimming pool, but the pump has been broken since about March (so basically I’ve been cleaning it manually the entire summer). I have had a multitude of people out to troubleshoot and try various things to fix it, to no avail. Several pool technicians have looked at my pool, shaken their heads, and said, “I don’t know what’s wrong, this should be working.” Now, I’m not a pool expert, but I am an experienced engineer and troubleshooter. What I said to them was, “OK, so if it looks to you like the pool should be working, but it’s not, then that means something you think you know is wrong. What is that list of things? Can we double-check those items?”
Eventually, this week we did finally get the pump working again. A new technician who came by took a look and said, “I think the problem is here.” Now, we had already had a different service provider come by and take care of that component, but I decided to have the tech redo the service for that component anyways. And sure enough, that fixed the problem! This of course raises the question of whether the prior service provider did the task incorrectly, or not at all, but that’s beside the point. The point is, all the previous troubleshooters had assumed that the service task had been done and was not part of the issue, but it was. Something they thought they knew was wrong.
The key to implementing this is, when you are troubleshooting, or helping someone troubleshoot, listen for this indicator: “That’s impossible. This should be working.” At that point, the way forward is to stop and think through all the things you think you know, and start thinking about which of those things, you just might be wrong about. If you think you are seeing the impossible, then you are not seeing what you think you are seeing*. There’s something different than what you think going on somewhere.
And THAT is the art of troubleshooting.
*This is another one of my phrases I use all the time.