I swapped the stereo/media-centre out in a Kia Sportage for a secondhand one that is 1 model out. The original units NAND died locking it into a boot-loop; but the radio/audio continued to work (so I know the speakers and wiring are still fine).
The only external difference between the two units is a decrease in the model number and the new unit has a 14amp negative ground (original unit was 5amp negative ground)
Internally the units have an identical board serial number; but the replacement unit has a capacitor in the blank space of the original and a black block marked amp; I assume this is the issue but am not sure how to resolve it.
The rear connections are identical on both units