Yes, I also noticed that many devices were actually connected to the 5V rail, but I didn't know that it's all of them except the SD card. That is of course quite dangerous with the failing voltage converters in the Lynx and of course anybody who tries to bypass the switch MOSFET with a line to the headphone jack will instantly fry it. So if there is a chance that every single chip on the cart is toast, there is indeed not much of a point to salvage it.
Thanks for the swap offer, I sent you a DM regarding that.