Printer Shutting Down UP Plus 2

I when to change the filement from PLA to ABS last night. It removed the filement fine, When I went to add the ABS the printer turns of the heating element and then shuts down, like it has un-initalised. You need to press the initalise button to get the printer activated again.
Is this likely to be the fan or the heating element giving a faulire signal. How can I test for the error.