Thanks everyone for the advice and help.
The 5.0 GHZ signal is back ... but not as a result of anything I tried.
First I examined my cell phone (Samsung Galaxy Note3) settings and couldn't find anything changed or missing set. Power savings was not on and toggling that did nada, likewise powering down the phone.
Visually the router (it's LED) was indicating that both radios were on and therefore broadcasting. Most probably a flat lie, read on.
Then I signed on to the Router Console with 192.168.1.1 and the ID/Password I had set up.
Every setting was as I had left it in December of last year. No indication of problems or errors, also a lie. There was a "new firmware available" flag showing but I didn't want to make that change in case it would complicate a problem.
I _did not_ view the log, Wrong decision

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Next from the Router Console I did a router reset, which accomplished nothing and knew I was lost so I signed off for the night.
BTW I mean - nothing I was trying was causing the 5.0 signal to show up on my cellphone

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The next day there was a power outage at our house (thank you Florida Flash and Flicker) and _everything_ reset. When I got home the Microwave was displaying PF, for Power Failure (!) and I just happen to look at the WiFi list on my cell and the 5.0 signal was back.
Our whole house has a Utility installed lighting/surge protector on the incoming power drop and I'm concluding that the 5.0 GHZ signal stop because of a (previous) power failure and the next power failure toggled it back on.
But I did learn that I didn't have any independent way to check if the 5.0 GHZ radio was on or off (booo!)
After I was satisfied the the cellphone and the router were communicating on the 5.0 GHZ signal I did download the firmware up date and the ASUS is healthy once more.
ROUTERS LIE, don't turn your back on them, they are not to be trusted, ever


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