Geeetech A10M upgrade to SKR 2. Help needed please

Hello all. I’m embrassed to tell you how many boards I’ve killed trying to upgrade my A10M to an SKR 2. I bought the A10M as my first printer, probably not the best idea. The GT board died one day when I switched the printer on so I decided to to upgrade to 32bit. I didn’t count on the molex connector, lack of information and version 1/2 differences of the A10M. There’s a guy on YouTube who has videos on upgrading his A10M to an SKR but it’s a 1.4 board and the printer is V1. The wiring is colour coded different and there’s some other subtle changes as gotcha’s. I spent a lot of time tracing and identifying the wires leading up to the hot end breakout board, I’m pretty sure I've wired everything correctly but being distracted by the hot end what I didn’t do was rewire the steppers to the correct pin positions for the SKR 2.The new boards were fine over USB power and I was able to install firmware without issue. The LCD saw the board as did my laptop. As soon as I power with 24v the board isn’t recognised anymore. The hot end fan operates so there’s a 24v circuit intact, but “no printer found” on screen. I’ve tried re-flashing firmware but no response from the board. I have a bltouch but it wasn’t connected and a new external mosfet which I’m sure is wired correctly. I’ve fitted ferrules to all the appropriate connections and where wires required extending all are soldered and heat shrunk so there shouldn’t be any shorts. Is it likely the steppers being wired incorrectly caused the boards to die? There was no obvious signs at the time and inspecting the 2209 drivers there doesn’t seem to be any blown components. (Understand any damage might not be visible) Another fried board and the printer is likely to become an underwater hazard in my nearest lake! Help save a swimmer and my sanity please.Thanks