the button exists but it is not a button, if we get a solar storm like in the 19th century the entire electric grid will be shut down all transformers fried. guess what there are not enough made to replace them. Months or even years till all the grid is working. a week without electricity causes panic just consider months, total breakdown
It's not so much they don't make the large high voltage transformers in large quantities, it's the fact they will need power to rewind them and stove and varnish them.
If, we got an X class flare of say 8 or higher, every modern form of transport will grind to a halt, the solid state devices in the vehicles onboard computer will be fried. Almost every modern semi prime mover has a computer for the fuel injection system, locomotives on the railroads do too.
Imagine a world without electricity and transport!! No communications, Cities would be a death trap of rioting, gang warfare, sickness and disease.
I'd imagine the police would grab their families and do their best to flee the cities, I know I would!
This could be a real test for the military's electronic equipment too, which has supposed hardened semi conductors...
Then there is the very real EMP problem, if one of our "friends" like China carried out a pre-emptive strike with a 1 megaton device high in the atmosphere over the mid west, we'd be in the same boat, dead in the water...