MMM just stoped

Hi all, I was racing my caster buggy last knight and in the 3rd race the buggy just stoped no lights no smells but the esc felt a little warm but the fan was not working either but exspected if nothing else is it wont be. Thought it might have been the switch causing the problem so i removed it but still will not show any lights or power up at all. Checked all conection and changed batteries but still no luck.
It dose have a small rattle inside of it when shaken and im suspecting somthing may have come off the bottom of the pcb. I thought i would try to conect it to the castle link software but found the adaptor got hot very quickly, lucky i was halding it at the time and noticed it and unpluged it strait away.
Should i open it and have a look or just send it to castle as is.