430ex II problem...anyone any ideas?

New batteries and the lot.

Reset settings via camera.

makes that hum sound when powered on (think the hum originates from the flash head for the reflector motors).

LCD comes ob and all LCD functions work but the pilot light does not come on or fire.
On or off camera.

http://youtu.be/u74W7z​w-iIM

It's probably dead. I did NOT hear the flash recycle sound in the video, which to me is the giveaway.

I've had 3 430's die on me in a similar fashion in the past 4 years. In a pinch I've used a dead one on-cam as a flash assist device whilst triggering via pc-port a couple of off-camera flash, but obviously having the flash on cam actually totally functional is best.

Canon repairs these for far less than the cost of a replacement unit.

If it's not even firing when off camera, then there's almost certainly a fault with the unit itself. You're probably going to have to get it repaired.