It usually makes sense to have a slew of tests formally defined and to write a test that functionally checks every subsystem. If you don't test, Murphy ensures

It usually makes sense to have a slew of tests formally defined and to write a test that functionally checks every subsystem. If you don't test, Murphy ensures you always make errors before ordering next revision boards. Rushing never helps. Assumptions always fail. Hardware's very unforgiving coming from software, just because our brains are too impatient and we feel it's OK to cowboy all the time. For most of my boards I wound up writing a bunch of tests that automate current readings across different power rails while stepping boards through different states. This verifies that subsystems are moving approximately how I expect them to move without having to make too much of a manual test, and allowing full validation of remote control round trips. Really makes proper testing easier. For a camera, having an LED rig on your test jig to check pixels move in the right direction when lit in different colors would be a reasonable approach. Cool fix though... at least until the components age and the net properties shift subtly...