Flash on clash colour, lit AV and sound still work, but the main LED colour does not?
Sounds like a loose wire that's connected to the main LED colour. Heavy impacts can jostle wires loose from their connection, which isn't unusual at all ... but it can feel unnerving when you're not used to it.
To find out if this is the issue for sure, you'll need to slide out the LED module and unscrew the housing. You'll be able to see the wires connected to the LED pad and if I'm right, one of those wires will have come off the pad.
From there it's a matter of soldering the connections back together and you're good to go back to heavy duelling. These LED's can handle it, so don't stop having all that fun with your saber