Of course there is also the situation in that contacts in switchgear which
carry little current and voltage can often get oxidised. I wonder if these switches carry much more than the voltage from the logic on the board, and only a tiny current. "Best practice" would call for contacts of precious metal like gold or platinum, and a design of switch that gives the contacts some "wipe" when they come together so that they have some. Too much modern gear has (of course) neither of these features.
You can try cleaning the contacts with something like this "bootlace"
http://www.canford.co.uk/BANK-CLEANING-TAPE
and / or very careful cleaning with a fine diamond contact file.
Good luck with a repair. It looks as if you have the fault, which is usually 90% of the work in these sort of things.
ETA I just read the part about you having it fixed! Excellent!
Hi Dave,
I'm not sure if I have already said this, but earlier I opened the Stalk, and cleaned it, some of the contacts were eroded, and the grease was green. I checked the switch was switching, and thought that was it, but it seems the green 'Verdigris' had seeped into the molding out of sight, and needed circuit cleaner to wash it out.
Camerart.
