Based on appearances, the board has a tight cluster of components laid out similarly to a contemporaneous iPad. The rest of it seems like a vast empty wasteland

Based on appearances, the board has a tight cluster of components laid out similarly to a contemporaneous iPad. The rest of it seems like a vast empty wasteland, lightly populated with debug terminals, ports, and compatibility shims which make it work inside a Mac mini chassis. Chances are the breakage caused a power rail to short and the “repair” fixed the short while leaving one or two debug points inoperable.