Hi LHD,
yes, you can take these apart and clean them. (spraying contact cleaner into the hole in the back wont do it)
it is not difficult, but you must exercise great care in keeping things oriented the right way, or you will never get it to work again.
first, unsolder the switch from its PC board location. you must do this in order to take the switch apart.
next thing to do is use an Xacto knife to cut around the edges of the white plastic dots on the back of the switch.
DO NOT! just cut the whole tip off. you need to re-melt the center portion when you are done in order to hold the metal plate in place.
just cut around the edges until you can pull the metal plate past the white plastic "nubs".
before you begin sliding sections off, position the metal shaft so that the flat parts point out to the sides of the switch.
you need to make sure everything goes back on EXACTLY the way it came off, and you dont want that shaft turning a lot, because that could cause you to put a piece back in 180* off.
start wiggling the sections back and lay them on a table in the correct orientation so you will know how they go back in.
once you get the first piece off, you will see a disc with copper etchings on it. MAKE SURE you know which way it came off, because if you mess this part up, you will most likely never get the switch to work again.
once you get all the sections off and laid out nicely, you can put the shaft assembly aside. do not remove the shaft from the plastic assembly.
there is a spring underneath that ball bearing, and both will go flying off never to be seen again.
now you can carefully clean each switch section and each disc.
i like to give all the pins a little bend to make sure they are all making good contact, but again, be very careful.
put the switch back together, put the metal plate back on the back, and use a hot nail head (or whatever you see fit) to press/melt the little plastic nubs down so they will hold the plate on.
thats it!
good luck with it,
LC
