(warning: contains gross stupidity)
OK, so in a fit of inattention while I was refitting the battery after taking it out for charging* I managed to briefly connect the battery terminals the wrong way round. Naturally, something went phut and now I have a dead, or at least dormant, bike (a 2000 boxeye 600, for reference). With the battery refitted the not-bloody-stupid way round, turning the ignition on has no effect at all - in fact, there is no circuit between the battery terminals with the ignition key inserted and turned to on. No dashboard lights or LCDs, no fuel pump tick, no nothing (which sort of follows logically from the above, I guess).
All fuses in the fuse box and the big 30A one tested and OK. Battery producing 13.4V
So, any suggestions as to which bits am I most likely to have fried, and how I should test them? Big relay under the left hand side cover next to what I think is the flasher relay? That black box under the toolkit that I've never actually identified? ECU? Something else? I didn't really notice where the phut came from but at a pinch I'd say to the right of the battery compartment somewhere.
* Needed charging because of a separate bit of stupidity, but not a relevant one as far as I can tell
Signed, A. Numpty