More likely than not, the issue is with the Chromecast app and not with your Galaxy S7. Wireless connection tends to lag over time. Be sure to turn it on and accept screen Mirroring signals from smart devices. I can term AirPlay as the 'Brain' behind screen mirroring. Locate and touch the OFF slider to turn the Screen Mirroring ON. The book is divided into big categories, with annoyances grouped by topic. Fixing PowerPoint Annoyances, presents smart solutions to a variety of all-too-familiar, real-world annoyances. Enable the screen mirroring setting on your mobile device. Then start mirroring again from your Mac. 1) Download and install the Mirror for Samsung TV or the Mirror for LG TV app via the App Store (a $4.99 value).