There's enough detail in your post to identify the book as "lights out" by Crawford. There's at least three books with that title and insane as it sounds Ted Koppel wrote an EMP realistic fiction on the exact same topic, yeah that Ted Koppel you're thinking of... Crawford's book is ground zero for the entire genre AFAIK and maybe 25 years ago he was discussing early revisions of it online on the internet probably on usenet. Way back when it was unusual for book authors to be involved on the internet or BBSes before "everyone's on social media"
I was astounded to check out the copypasta near clone books on Amazon. Much as its impossible to buy real cables or real chargers on Amazon we're getting to the point of there's going to be 1000 copypasta for every real or original ebook as per the linked story.
There are five interesting points about the original book and the copypasta phenomena and EMP in general.
1) I've done the EE stuff and read the QST/QEX articles about hardening radio gear for EMP and some of the professional stuff and I guarantee nobody writing or talking about the topic has done even that much research. From a commo point of view its harder, faster rise and fall lightning and you have to do lightning protection anyway, so... People who fail at lightning protection like to claim nothing can be made lightning proof; their either pedantically correct that you can only reduce the rate of damage by a factor of a million or so which is usually economically useful, or they're bad or non- engineers and they don't know what they're doing.
2) To the technical illiterate its all magic so its a variety of technobabble with no relationship to reality. For example actual (simulated) nuclear EMP testing of modern cars is pretty much a bust. In the genre all diesel electric locomotives burn out which is technologically speaking, hilarious. Its almost like zombie fic where the zombie stands for anything but actual zombies. This hand wavy magic IS how the general public sees EE or telecom stuff. Sure to people in the know their idea of magic is all ha ha funny alchemical but the fact remains there is no reason or rationality involved in the general public vs EE stuff.
3) The prepper - survivalist community is not by any means unified and this kind of fiction sells very well to a very small subgroup although most are interested in surviving hurricanes or blizzards while living in rural areas or living thru likely economic collapse (along the lines of 1930s, 2007, etc). I would guess the average city slicker wouldn't last more than a year in the country, so some prepper stuff is very much "back to the soil" propaganda. I guess I'm a prepper because I have a decent first aid kit in my car (and some training to use it and up to date CPR cert etc) and I have a fire extinguisher and some MREs and stuff in case I get stuck in a blizzard (which has in fact personally happened to me, and because I was prepared its an incredibly boring story, also I've been trapped in a house with no electricity during a blizzard and that was also very boring, oh and I was trapped in a cabin after tornados went thru the area and covered all the roads with trees, but I'm old, this stuff doesn't happen every decade, etc, none the less you can prepare or you can prepare to suffer, your choice...)
4) Most prepper fiction is highly escapist like bad sci fi. Real societal collapse looks a lot like Venezuela, Brazil, "the middle east" during periodic wars, Somalia, West Virginia (only halfway kidding) etc. Everyone's not gonna die although a lot will, and its gonna suck a lot worse than you think no matter how pessimistic you are. But we come from a long evolutionary line of survivors and even in the worst case its mostly not that big of a deal.
5) Some of the tropes are just funny. Outlaw cannibal biker gangs. The retired Marine who either saves everyone or is a complete PITA or both. Hillary is gonna take all our gunz.