Bill,

The problem with using WD-40 is that it never really dries. Consequently, if it comes in contact with some of the surrounding components it can really cause problems. Contact cleaner dries almost immediately, leaves very little residue, and is not a good conductor of electricity. It was originally formulated for cleaning TV tuners in the 1950s. Also, be sure to use that stuff in a well ventilated area. The vapors can be deadly if inhaled.

Good Luck,

Gary