Wait until dark
Turn the lights on, does the dial light go, ok it's got a good ground then
Take the chrome cover off, is there 12 Volts on the + terminal when the key is turned on, ok it's got power.
Still doesn't go
Take it off the bike, does it rattle when shaken, if yes the counterweight has fallen off
Send it to someone to open up and re-glue it back on,
I don't care what anyone says it's a sod of a job to open one of these up