Ever since @D'tar posted it in a help thread about the all-too-common "SAS" (silent amp syndrome) I've been impressed with the simplicity and usefulness of his test for input jack wiring on Fender amps. As we all know, the clever design, wire and resistor topology, possible variations in jack rotation, and especially the complexity of the 4-input (5E3 etc) version make for a lot of possible ways your signal doesn't actually make it intact from guitar to V1. I always try to look up and quote his original post when I see Fender-build SAS, but finally decided it'd be easier to steal the darn idea and stick it in a little Excel table I could post when needed. As usual, his way is complete, simple, correct; any mistakes here are mine. I post this here not only for general consideration but also to make sure he gets all the credit. Then I can stick this in SAS threads and let him use his infallible eagle eyes to spot the one tiny wire among hundreds that got lost on its way home.