The other networks showed similar results so I decided to just replace them all. I was curious about the internal construction and dissected a couple. The resistors are just carbon powder and the caps look like ceramic cylinders.
I rebuilt the K4 network using plastic caps and metal film resistors on a little perf board. The 0.0015 uF cap is rated for 2,000 volts like the one next to it on the main board.
Parts for the other neworks will arrive in a couple days.
