Hello tbrucenyc,

Your question requires definition of "electronic" first.

Industrial remote metering and control started in the 30ties,

then a mixture of tube electronics and electromechanic

and pneumatic devices.

So it is very likely that the very first nuclear reactors had

some electronics already. Whether this was necessary or

not to the operation of those reactors, I don't knows.

There is another factor: Many processes would afford

more  laber force to operate, thus making the proces/products

much more expensive, and/or wages were much lower.

Georg

The mail is sorted using automatic machines, technically it could be done by hand, but be prepared to wait a long time to get your letters delivered.

Your internal combustion engine has electric circuits for ignition at the very least. If you are using the strict sense of the word electronic, then that still counts. If you want to use that engine to power a car, then you will have to choose one with no ECU or other extraneous parts.

And then you'll have to drive to a garage which has old style mechanical petrol pumps, because the standard pumps won't be working any more.

I would highly doubt that the power grid would work as it is, given the complex monitoring systems that govern it. Similarly with power production facilities.

That reminds me of a power cut we had a few years ago. My computer switched to UPS, I shut it down, decided I could do no work without electricity so sat in a chair with a book. Ten minutes later my next-door neighbour was knocking on the window; he called in, "It's alright for you, you've got books. What am I supposed to do till my TV comes back on?"

What would still work, was the question...

I'm defining electronics as the use of vacuum tubes or solid state devices.

Many things would still work without electronics.

I'm not saying it wouldn't be difficult or dangerous.

Postal mail can still be delivered Old phonographs would still reproduce sound. Cars would  run without computers. Silent movies could still be shown. Lights and motors could still be powered by the grid. Nuclear plants could still have their pumps, control rod servo motors, and valves electrically driven.

What else would still work?

The telephone system would work, but long distance would be back to mechanical repeaters, and not be practical.

Relay logic could still send an elevator to your floor.