Hi I am a newbie here and to 3D printing - well electronics and mechanics in general actually. Learning a LOT. However in the process I have blown something related to my fan on my GT 2560 board. I know this as it went "poof" and there was a burning smell when I tried to connect a new one after I killed the old one by accidentally breaking the blades when removing it from the extruder (MK8). The new fan I was trying to connect was a 12v larger one so maybe that's why it happened? Anyways I have a couple of new ones on order but I don't know what to do about the fan connection to the board (board is working fine otherwise and I have a fan connected to another power source temporarily).
I know there are 3 fan connections on the board so could I alter my config h to use one of them instead? If so, what code would I need to alter? Simple instructions please

and while on the subject, if I want to add another fan for the heatbed, what code do I need to turn on for that? Also if I want to replace the part on the board, what would I need?
Thank you so much, any help is appreciated.
kindest regards from Australia
Jan