Hello, and thanks for the questions (and sorry for the delay). A properly designed Faraday Cage completely negates the effects of the EMP by preventing the waves that cause the damage from passing through. It can’t be partially effective and still provide any effectiveness at all. Fried is fried.

As for age, it depends on the technology. If it has a circuitboard, you can pretty much guarantee it’ll be fried. But what items would or would not have circuitboards depends on the that specific technology. Early computers used vacuum tubes (etc.), which would have been completely safe from EMPs. The tubes often needed replacing, but without compromise to the computer at large. That was up to the 1960s.

Could you please clarify a couple of points for me?

Does a Faraday Cage cause the EMP to have no effect whatsoever, or does it merely lessen the effects? And how old would the electronics need to be in order to survive?

Thanks. 🙂