OK as you know you must turn key to on position, turn switch to on position, squeeze brakes and hit run switch...Some Days I do all that and nothing happens. ...
I had the same or similar problem on my 2005 GV 250. Here is the symptoms:
1. kickstand up & run switch on - hit starter and nothing happens. Starter does not turn over. Battery fully charged.
2. The digital LCD speedometer screen does NOT go blank the way it normally does as soon as the starter button is pressed - which indicates that the only problem left is the the left brake interlock lever switch.
Note: Even if the kickstand is down and the run switch is in the off position - the starter will still spin the motor but it will not start. The only thing that prevents the starter from moving the motor (assuming everything else is working) is the brake lever switch - same switch that triggers your rear brake light.
The test: squeeze and hold the rear brake (left brake lever) and if the brake light does NOT come on then the switch needs to be replaced or cleaned. It costs $20. I opted to remove, carefully open and clean the corroded contact on mine and have not had a single problem since.
If the brake light goes on when the left lever is squeezed, then test the
starter relay as zombie suggested.