Calc

Hi guys, I dropped my bike this morning on my way to work (first ice of the year ), picked it back up and it started just fine and I went on my way. When I've come to go home it wont start. The starter motor kicks over and it feels like its trying to start but just cuts out. I get the low engine noise for 1/2 a second. I tried bumping it and it got the same thing. Battery and fuel are fine I think it might be the immobiliser or fuel injection cut out thats stopping it firing but I dont know how I would go about checking those (mechanical novice here) Any advice or other ideas? Thanks