(post moved to Electrics forum)
When you turn the key and the clocks (should) sweep, you should also hear an obvious whirring from the fuel tank, as the pump primes. If it doesn't, you'll find two small relays under the tank, on the l/h side of the battery. They were under the seat on older models.
NOTE! try to avoid lifting the tank if it's more than half full, as it puts excessive strain on the hinge, this is not so bad if you have a plastic tank model.
One is the fuel injection relay, the other is the main one. try pulling them out and swapping them over, if you then get nothing at all the FI relay was dead. They were about £6 each from Moto Rapido last time I bought some. I keep a couple in my toolbox now, just in case.
Other obvious things to try (but often overlooked)
Is the kill-switch set to 'run'?
Is the neutral light working? if not the bike may not start with the stand down or if the the clutch lever isn't pulled in (this differs a little from year to year)