Power Outage and now modem won't work (AC1750)

If you're under a year, I'd open a support ticket with netgear for replacement.  Power surges and power outages can wreck sensitive electronics fairly easily. Plus if you attempt to replace parts, its going to void your warranty. 

You're kind of in a hard place. the c6300 is a combo device so you can't manually force it to take firmware using a tftp procedure or you could try this. You've tried the reset but you could always do a 30/30/30 reset and see if that works. While powered up hold reset for 30 seconds, unplug route for 30 seconds (while still holding reset), and then plug back in (still holding reset for 30 seconds). If this doesn't work, I'd go the support route for replacement. A good surge protector or backup power supply might be a good purchase in your future if this happens routinely at your residence.