2 nuclear option added
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One additional point - if a major nuclear power knows exactly what is coming, they have a never-to-be-repeated chance for a pre-emptive strike. Let's say country X knows its missiles will take 15 minutes to reach their targets in country Y and vice versa. If country X launches at 11:44:30 then their missiles will have time to reach their targets and detonate, but unless country Y can detect the missiles, assess and confirm the threat, make a decision to launch and get their birds in the air within 30 seconds, their missiles will still be inbound when the magic takes out all electricity, including the detonation circuitry. Without a detonating mechanism, country Y's missiles will just slam into the ground, contaminating a tiny area with waste, whereas country X's missiles all detonated.

Edit

One additional point - if a major nuclear power knows exactly what is coming, they have a never-to-be-repeated chance for a pre-emptive strike. Let's say country X knows its missiles will take 15 minutes to reach their targets in country Y and vice versa. If country X launches at 11:44:30 then their missiles will have time to reach their targets and detonate, but unless country Y can detect the missiles, assess and confirm the threat, make a decision to launch and get their birds in the air within 30 seconds, their missiles will still be inbound when the magic takes out all electricity, including the detonation circuitry. Without a detonating mechanism, country Y's missiles will just slam into the ground, contaminating a tiny area with waste, whereas country X's missiles all detonated.

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It's the end of civilisation as we know it

Assuming that everyone knew that this event was coming and exactly what the effects would be and exactly how long it would last, civilisation might be able to pick itself up afterwards. I really doubt it though. The planet simply cannot afford to basically have all of its infrastructure go on strike for a week. Lots of factories, foundries etc could not be restarted if they were completely shut down for 24 hours, let alone a week. Most large powerplants could not be restarted for a prolonged period even if the shutdown was known to be coming, so it would be much more than a week without electricity for the large majority of the population. In mild weather the critical effect is loss of water supply - over 70% of the US population live in urban areas, with only a small number having access to "natural", potable fresh water close to their residence. In hot weather the water supply issue is even more critical and compounds with the lack of air conditioning. In cold weather the lack of heating will kill people - people living in apartment blocks cannot just "start a fire", even assuming anyone can start a fire (see below).

While you have not explained what the previous weekly occurrences have been, they do not seem conducive to a stable economy. I would suggest that the current 13% of the US population who live in poverty would have increased over the six months of unexplained events. These people have a hard time feeding themselves when everything is working "normally". In uncertain times when everyone who can afford to is stocking up on canned food and shotgun shells (even if the latter turn out to be useless) the poor will be struggling even more, they certainly will not have a reserve. Within 48 hours they will be fighting the "haves" to get food to feed themselves and their children, and given that the loss of tech means that almost everyone is down to using knives and clubs (or their mysterious superpowers) they are on an even footing.

A quick note on the psychology here - people do not deal well with uncertainty. If the government has all of the facts and was able to tell people in advance what was happening, how long it would last and how they would be looked after once it is over - most people still will not be making rational decisions after a few days without food. Neither will the people who feel threatened by them.

In short, lack of water, climate effects, and fighting for remaining food will probably kill 30%-70 of the urban population after the week (or two plus) before electricity can be restored to some areas, depending on time of year and associated weather. Disease will probably kill another 10-30% of the urban population over the next few weeks. However, the situation is actually worse than this...

No combustion or chemical reactions

Your responses to comments regarding the "no guns" limit appear to read as "no combustion". If my understanding of this is correct - that is, fires, fuel-driven power plants and fuel-driven vehicles are permanently inoperable - then there is no more modern transport or industry. Ever. It also means that except for the few solar BBQs around, there is no more cooking until/if the electricity is restored - this renders lots of food staples inedible. At this point the nationwide casualty rate within 3-4 weeks is going to be well over 90% and the technological basis of our civilisation is gone. The small stocks of electric cars etc will be utilised by the survivors, but without energetic processes available for manufacture they will not be replaceable.

I have deliberately omitted examining the neutralisation of firearms because their absence has no effect on the long term picture. For the short term, loss of communications is a far more critical problem for law enforcement. The loss of firearms may be psychologically traumatic to Americans on both sides of the law, but there are both historic and current examples of police forces, such as the British, not issuing firearms to most officers.