Lost an option to view of ipad and smartphone

[DURHAMLAD]

I'v recently disconnected tv and connected it back up, I'm connected to wifi ok but now I don't have option when I'm on YouTube to screen it on my telly, the ikon on the smartphone and ipad isn't there 

[Anonymous]

Hi there

If it worked OK before, I would probably reboot the TV by pressing and holding the power button on the remote control for about 10 seconds.  As well as rebooting your devices. 

If its never worked before, have you installed Google Cast on your devices (i.e. iPad : https://itunes.apple.com/gb/app/chromecast/id680819774?mt=8 )

Cheers