Ain't gonna happen. For one thing, we've got loads of scrap steel laying around, so that and a hot fire puts you to late iron age.
And there are enough geeks around that we'll be back to the late 1800s, early 1920s in a few days.
/johnny
How are you going to accomplish this when our lives directly or indirectly done with a computer?
Equipment that is purely vacuum tube based and shielded in some sort of chassis would be unlikely to fail. Even its capacitors would be kept mostly out of harm’s way. If the capacitors are of some materials like mica, they will puncture but not short out when overvoltaged.
Industries today are connected by computer. Just how is this giant leap going to be done?