How much later is later? 5 seconds, 5 minutes and 5 hours are very different scenarios. Or if you prefer what happens to someone with a computerised pacemaker in all those scenarios? 5 seconds you might not even notice or it might just be really unpleasant, 5 minutes without blood flow leaves you dead or a vegetable (though someone might be able to do CPR) and 5 hours is very dead indeed.
A few shows deal with "what if humans suddenly vanished" and with that was what if power went out which is kind of similar. Life after people probably being the major one.
We might also have to figure out what you count as a computer -- I can make an adding machine and thus computing/logic machine using relays, and actually still do from time to time.
They don't crash unless the contacts get welded together.
Equally it is unlikely to happen to just digital things -- it could happen with a large nuclear emp blast, solar flare/solar storm or maybe a lighter/diffracted edge of a gamma ray burst. Those however would likely also burn out power infrastructure which brings a whole other host of fun and games to the party.
Similarly we would have to consider what all the big industrial consumers of power would have happen. Many things have safety interlocks and backup generators, many of which are mechanical in nature.
I am also back to the timings for something like planes in the air and other computerised transport. Being without ground control and radar for those various lengths are very very different scenarios.
