I thought about opening the head unit up to see if anything was immediately apparent. The On button would light up, but the moment the faceplate was installed, it would blow the radio fuse (B2) in the box...so it's shorted out somewhere inside there as the new one works as it should. Unsure if opening it up would get me any further than a chance to break stuff even worse or not, especially since my electrical testing skill set is not well developed.
I wouldn't be able to tell what to fix unless there were an obvious brown toasty sign of electrical short or broken connection somewhere. That kind of fix isn't so user friendly.