It won't be a fuse since your brake lights still work, and those are on the DC circuit...
The AC circuit for headlight, tail light and "dashboard" lighting doesn't have a fuse...
(Kymco must have chosen a short-circuit proof combination of stator and wire size...)
I don't think it will be bad earth either, since the brake light and high beam work, and they share their earth circuit with the low beam and tail light...
Check for damaged wires, it's possibly a short circuit from a wire for low beam to earth (which is called ground in a system like this actually)...
Also check the connectors for both light switches at the handlebar, there might be one or two loose contacts, I've seen them come loose and stick out of the backside of a connector sometimes...