I agree with what Randy is saying EXCEPT - I would not remove the "brass valve receiver" in photo 8 of his link. The o-rings that seal this part to the grouphead have the size designation OR105 - an Italian o-ring sizing spec. After 10 years, they have grown accustomed to their squeeze. Are replacements available - absolutely - about a week from our on line friends. Are replacements absolutely essential? - maybe yes, maybe no.

Check your OPV flow first - that requires you lifting the cover off your reservoir and picking up the right tube - about 10 seconds. Once you eliminate that (or not) as the source of the problem, then proceed as Randy recommends regardless of the outcome.

You need to be a little more definitive . . . so . . . unplug machine, remove reservoir, remove (4) screws holding top cover in place, remove top cover and take a few pics. Post those pics and help MAY be on the way.

Ann Arbor - University of Michigan - there's enough technical "know-how" in that town to easily fix a Rancilio Silvia. Madcap coffee is in Grand Rapids - is that close ? They should certainly have "fix it" leads.