Originally Posted by
Cyanotical
we can infer from several facts:
digital power supplies are not a simple device, thats why you don't just put any old PSU off the shelf into a computer, they are not the same,
AC-DC adapters are cheaply made, and lack many of the safety features of proper powersupplies, including a grounding pin
when properly designed a grounding pin is used to dump excess voltage in the event of a surge, without one power has to go somewhere else
now about power being the culprit:
OP did not have problems before the power outage, that means we could very safely eliminate non power related sources of the problem, since it was the event that changed things
again, inferring from experience and knowledge of how computers and digital logic systems work:
putting both of the above together means we have reasonable support for the idea that a surge or dip in power either when the power went out or turned back on caused damage to the modem
since the modem works for a while before having problems, we can look at components that are not initially used, but will get used over time, a good place to start is memory, as the local cache fills it, reaches a location in the ram that is damaged, and this causes either a halt or infinite loop (pretty much the same thing)
again, inferring from knowledge and experience, this is a field where you have to be intuitive, if you have to wait for hard evidence, you will spend a long time and a lot of somebodies money doing so
this is not an urban myth, the myth is that cutting power to your computer can harm the hardware, while there is always a remote chance, the odds are very slim
a power outage, ie not from a switch, is a real and known problem, idk where you are getting this idea that it's a myth, but look into brownouts, and voltage regulators
voltage on a standard VAC115 socket can vary on average by as much as 20 volts in either direction, but when an outage occurs, hundreds of volts can be sent down the line for a second or so
or in the case of California in the summer, rolling brownouts can go on for hours
these are not myths, but well documented occurrences
'A' would be correct, 'B' is pretty much what i suggested in the first reply, a small cheap UPS will work for a modem and router
this just sounds like tier 1 phone support reading a line from a technical manual