BigTon

My 2000 SV650S died last week. I cant work out what caused it! Any help would be much appreciated.
Battery has past its best but was fully charged and ok. Rode about 8 miles to meet everyone then went about 20 miles and stopped to regroup, all seemed fine.
When I fired the bike back up (10 minutes later) everything still seemed fine but when I pulled off I my indicator light was flashing, fuel light flashing and I think oil light on. Also rev and speedo needles were bouncing back on forth randomly.
I pulled over and stopped but it wouldn't start again! No ignition lights at all! It seemed like there was no power anywhere? No lights, horn or anything
A few roadside checks showed...
No power with different battery or jump leads
Ignition fuse ok (swapped with spare just incase)
starter fuse (30a) ok (swapped with spare)
Sparking from starter terminals, engine turned over and started twice but cut out shortly after. Engine turning but no start since.

After getting the bike home i found that there is power to the fuse box above the battery but I've not checked any other components as i'm not sure where to start. I did notice when stripping the bike though that the clutch switch has been bypassed. Maybe this has caused something?

Also, the only thing that I did different to normal is when I stopped I just cut the engine cut off switch and left it in gear. And when I started it left it in gear, clutch in and pressed the button. I'm not sure if the would have caused something to go wrong?