[Ericus Rex]

I have a selector switch that occasionally drops a channel.  Tapping the knob brings that channel back to life.  I suppose it just needs some cleaning.  What's the best way to go about doing this?  If it makes any difference it is an open switch, not sealed.

[gerald porzio]

So much the better that it's open. Unplug the unit, & remove the case. Spray switch w/ tuner cleaner. I have ELC-PS on hand. Rat Shack has their own probably. Some swear by DeOxit which is priceier. After spraying, work the switch thru all inputs 1/2 a doz. to a doz. times. That should do it. It's pretty wham, bam, thank you mam.