Hi, sounds so frustrating - especially on a newly purchased machine. I've had my STR a couple of years now and I've not had any need to get my hands dirty other than the usual maintenance (reaching out to touch wood at this point).
Also worth mentioning that I'm not a mechanic. But I have been on this forum for a while & seen what issues others have had.
So, having replaced the fuse first time around, are the symptoms still as below...
1/ when you turn on the ignition, do you have any dash lights?
2/ when you turn on the ignition, do you hear the fuel pump prime?
If NO to both of the above I think I'd start looking around the headstock to see whether the wiring loom has been damaged as this is not an uncommon issue with these bikes. Also check for loose plugs etc - including under the tank.
I'm sure someone will shoot me down in flames shortly, but I guess you have to start somewhere.