One reason why your Cyrus One or Two may have an intermittent input
By ARS, Jul 22 2012 08:09PM
The input selector on all the Cyrus One and Two models is a high quality Japanese switch made by Alps. However it's open (as opposed to sealed) construction does expose it's silver plated contact surface to atmospheric pollutants, dust and whatever else is in your living room! Eventually a tarnish/dirt layer forms on the more exposed rear most portion of the contact surface primarily made up of not so conductive Silver Sulphide (not oxide as some think) and thus the audio input fails to reach the output.
Although not for the faint hearted this switch can be desoldered, carefully dismantled and chemically cleaned and polished to as new condition (incidentally using much the same techniques used by the author in the broadcast industry for cleaning the silver plated Klystron tuning cavities on high power analogue UHF TV transmitters when they became twitchy and noisy to tune!) This picture shows the contact surface with a 20 year old tarnished one upper and a restored one lower which should have another 20 year lifespan - useful as these now appear to be obsolete......