power, but not turning over.

[lincs1963]

Got a bit of a strange one, Y reg thou, spent most of last 3 months tucked up in the garage. Wheeled it out today to access some of the other junk we store in the garage, thought "may as well fire up the bike while it's out". Key in ignition, fuel pump, exup etc whirry noises, push starter button and .............nowt!
First things I checked, kill switch in on position, check.
It does have an immobiliser fitted should I suspect this or am I just being a div and overlooking summats obvious?
Any suggestions greatly received chaps, thanks, Neil.