Have you seen the TV commercials where a uniformed guy in a bank watches a robbery in progress? A bank customer cowering on the floor tells the guy to "Do something!," and he mildly tells her that, "I'm a security MONITOR, I only tell people when things are going wrong, I'm not a security GUARD. By the way, things are going wrong."
That's a good explanation of planter seed monitors. Some planter operators mistakenly assume that anything shown on a seed monitor display is gospel. The gospel, when it comes to planting, isn't displayed on the seed monitor. It's what's in the ground behind the planter. If the seed monitor says there's a problem, say for example, that one row isn't planting at full rate, or that its not planting at all, it's up to the operator to get out of the tractor, dig seeds, and see if the monitor is lying. I can't count the times I've received phone calls from customer who declared, "My planter is planting high (or low)," or, "I've got one row that's not planting right." When I ask how they know, they say, "My planter monitor says so."
Folks, I don't care what your planter monitor says until you've got out and checked what's actually going on behind the planter. Once it's confirmed that, yes indeed, row 5 is under-planting, or that the down pressure system on row 10 is "light," then we can use the monitor to help decipher what the problem is. We can switch the questionable seed meter to another row and see if the problem switches to the new row. We can increase vacuum, or down pressure, or change air pressure and watch what the monitor tells us in order to help fix the problem--but only if we're sure the monitor is telling the truth. And the only way to confirm "truth" when it comes to planting is to dig.