Could not communicate with your Chromecast: how to fix it
ChromecastがWi-Fiに接続できない時の対処方法
Google's updated Chromecast with Bluetooth also has better 5GHz Wi-Fi
Google Chromecast – 1080p, Supports Wi-Fi 802.11ac (2.4GHz/5GHz), HDMI, Micro USB (Power), Works with iPhone®, iPad®, Android Phone/Tablet, Mac®/Windows® Laptop, Chromebook, Black - GA3A00093-A14-Z0 at TigerDirect.com