I just went into the basement to put insulation on the pipes.
Then I saw the drop of water on the drain cover on one of the valves.
It fell apart in my hand. The hardware store didn't have that size.
Four hours, three trips to the store, two valves, one tee, two elbows, several joints, and about a foot of new copper later my water system was restored to working order.
Oh, and if you disconnect the kitchen sink to drop a pipe to replace an elbow that was sitting right on the sill...remember to connect it again before turning the water back on.