nfshp253,
you are not the only one..... I had a AC66U (at office), a AC88U, and AC87U (both at home) fail on me all in a matter of 5 days.... Same symptom. Went down suddenly and became completely unresponsive. Rebooting will not come back, wireless lights are not lit. Factory reset not working..... Pulled my hair out (lucky I have a full head of hair) for 5 days and changed the complete infrastructure to Ubnt ER-X-SFP and UAP-AC-Pros. Took me a day to reconfigure and all I can say is much more stable than any of the Asus routers, and I had used AC66U/AC68U/AC87U/AC88U (Linksys and netgear before them) with ASUSWRT and RMerlin.....
Asus (and other brands highend consumer stuff ) are getting very expensive compared to the lower-end SMB/Enterprise stuff, which makes replacing the consumer-grade equipment with lower-end enterprise (if one have the skills to configure) equipment very feasible.......