KZ750N1 Spectre 82

Hi, lost all electrics in one pop - checked all fuses but still nothing? The bike still starts on the button- any ideas? Thanks.

Well, you couldn't have lost "all electrics" if the bike still starts.

Hi, front and rear lights, horn and neutral light ?

When you say you checked the fuses, did you use a test meter or just eyeball them? Glass tube fuses can look perfect, but have no continuity as the filament can come loose from the end cap, breaking continuity, but the break is not visible.