Check the gear cover has not been pulled away from the headstock, there is an interlock to stop the lathe working if you remove the cover.
Do you know how the chuck gaurd was imobalised? the easiest way is to just take the gaurd off the shaft but rotating teh shaft as if opening the gaurd will stop the lateh working, try turning it anticlockwise. I did teh same with mine and could not get it to start last week after a good clean up, I had turnd the mounting shaft while cleaning.
There is a small quick blow fuse on teh back of the head check that has not been knocked.
J