Nighthawk C6300v2 No WiFi even after factory reset

> I have a nighthawk that used to be my cable modem, but was moved to
> just being a wifi access point. [...]

   I'd expect that to have been a non-trivial operation.  See, for
example:

      https://community.netgear.com/t5/x/x/m-p/1463500

> Model: C6300|AC1750 Cable Modem Router Docsis 3.0

   That is your "a nighthawk"/"My nighthawk"?  C6300[v1] or C6300v2?
Look for "Model" on the product label.

> [...] My nighthawk is connected via cable to a cisco switch.

   What, exactly is connected to what, exactly?  (Hint: If a device has
different types of ports, then "connected to device" is not enough
detail.)  Is there some kind of router which is connected to your
(unspecified) "a cisco switch"?

> [...] neither SSID appear[s], and I can't connect to their last known
> values. [...]

   Do _any_ SSIDs appear/disappear when the C6300 power is powered
on/off?

> [...] The nighthawk used to get an IP address from my DHCP server,
> [...]

   That'd be the DHCP server in your (secret, unspecified) some kind of
router which is connected to your (unspecified) "a cisco switch"?

   I don't see how that would be possible.  The procedure in the thread
cited above has the user configure a static (LAN) IP address on the
C6300-as-WAP specifically because DHCP won't work in that situation.
But if the radios don't work, then the IP configuration details might
not be the biggest problem.

> I don't know what to do, and this thing is only 2 months old. [...]

   If a settings reset does reset the settings, and both the front-panel
radio LEDs are green, and a working wireless client device does not
detect any radio signals from the C6300, then I'd guess that its radios
are dead.

   "2 months" should be well within the hardware warranty, and still
within the 90-day free support period.  I might contact Netgear, and
complain: http://support.netgear.com/

   Visit http://netgear.com/support , put in your (actual) model number,
and look for Documentation.  Get the User Manual (at least).  Read.
Look for the LED descriptions and "Troubleshoot".