Maybe I am going mad. Or maybe I already am. Yesterday after doing the thick end of 100 miles with two very brief stops, I arrived at a friend's house for a brief chat, then went to leave. I am certain that upon turning the key to the 'on' position, absolutely nothing happened. No dash lights. After last weekend's whoopsie, I thought something might have nuked the battery in the time the bike had been stopped. Yet, upon switching off and back on, everything was fine.

I could not reproduce the fault. I couldn't set the key in a position between 'on' or 'off', and everything came on when asked. I am absolutely adamant that nothing happened that one time. If I wasn't imagining it, is this a predictive fail for the switch? At a guess, it's probably not user-servicable?

Maybe worth squirting some wd40 down the key hole and giving it a few turns on an off.

They can play up and work sometimes, or not.

The electrical ignition switch contact part is a separate item and is is mounted with 3 or 4 security screws to the bottom of the main ignition lock bolted to the top yoke, and can be replaced with any NC [maybe other] ignition switch, leaving the original lock/barrel in place.

I seem to remember that there are tangs can be bent up to take it apart to clean it, so have a look first.
I fitted a second hand switch part.

Funnily enough, after looking about, I was about to ask the question which you have already answered, Arsey! I've had a couple of flashes on and off while switching on recently, so I guess something is definitely sickening and will break fairly soon. The only question is whether or not an aftermarket switch might mate to the genuine barrel and save me having to use a different key. Don't seem to be any genuine ones going s/h right now. The electrical switch is NLA by itself, but Ha-Ha-Honda will supply barrel and all in one go for a trifling £171.80 inc VAT. I don't bloody think so... lol

Cant you take the switch to bits and clean the contacts? I've never seen a nc35 one so don't know if its possible, but done it on a fair few cars.

Get a secondhand switch and just use the electrical switch part at the bottom.
I am sure many Honda ignition switches are the same and will fit.