You can't really just open the computer and say "that looks bad, let's get a new one" unless it's obviously burned which generally doesn't happen.
The way it works is that you verify that suplies of battery + and battery ground are normal. Then you verify that all sensor inputs are normal. Then you verify that actuator outputs are abnormal and due to no possible cause other than a malfunctioning computer then you replace the computer.
This being a Ford with their rock solid computers, there's still about a 50% chance you were wrong and there was a bad connection at a wire terminal you still need to fix or some weird software glitch that could have been dealt with by disconnectiong the battery for 30 minutes.
That said, yes there are two tests that work well. Substitute a known good computer that has been working in another vehicle of the same configuration or try your suspect computer in a known good vehicle of the same configuration.
