This culprit may be the cause of your visit almost half of the time.
Of all the things that can be wrong when you're troubleshooting, there's one that is the culprit, oh, at least 50 percent of the time. One thing. And it's so simple that we usually wait until last to even look at it. Isn't that amazing? Fifty percent of the time this is the problem, but we don't look at it until every other possibility is exhausted. That could be days of investigative work before looking at the obvious.
If you hired a private eye at a mere $60 per hour at eight hours per day for two days, that's almost $1,000. So you hire this private eye and $1,000 into the job he or she says, “Ya know, I've looked at everything imaginable and there's only one thing left it can be. I don't really want to dig into this, because it's not my favorite thing to check out - frankly, that's why I saved it to last - but since there's nothing else left, I'll have a look.”