G'Day Bobby, so when you say it won't start, I assume that the battery is fine, the electrics all seem to be working, the kill switch is in the "on" position, the starter button turns the engine over etc, it just won't spark? If you've got a healthy 12 volts at the battery terminals, (Dyna's won't work much below 12 volts) read on.
Trace your wires from the Dyna ignition (blue/yellow/red) to where they're most likely connected, behind the right side cover, and make sure that they are still connected, particularly the power (red) wire.
It's usually connected to the power wire for the brake light switch, but regardless, whatever wire it's connected to, check to see that the connection is secure, and that (with the ignition key in the "on" position) there is power going to that wire. (I just use a cheap test light with an alligator clip and a pointy "probe" that I poke thru the insulation into the wire itself)
If the blue and yellow and red wires are secure at that point, you'll need to remove your tank, and trace the blue and yellow wires to your coils. These wires are only the "signal" wires, the power wires are black with a white trace, from memory, but again, whatever the color wires are that are connected (hopefully) to the other terminals on the coils. Once you've confirmed that there is power going to the coils, and you know that there is power going to the ignition as per your previous test, there's no reason why it won't start.
If it still won't start, (no spark still) double check your kill switch and your fuses, sometimes a good looking fuse can be busted, so it won't hurt to swap your fuses around, or even replace them with new ones, just to to be sure.
Lastly, if nothing else works, undo your headlight and remove the actual light unit, and trace the power wires from your kill switch/throttle assembly back into your main loom. From memory (again, but you can confirm with a shop manual) the two wires to be concerned about are either black with a white trace, or yellow with a black trace, and black. Just make sure that they're securely connected. By now, it should be running like a new one! Cheers, Terry.