Arrangement tab / 2nd monitor

Hi, I'm trying to connect a new Acer monitor to my macbook air. I'm running El Capitan.

1. I can't see the arrangement tab when I look at displays within settings
2. If i do the 'detect displays' nothing happens.
3. The monitor shows 'no signal' on it's screen.

I have it connected directly from my thunderbolt port on my mac via a Belkin macbook to HDTV cable into the Acer monitor. Is that right? I don't need any other adaptor?

Any ideas anyone?

Thank you.

I had this issue when I had my MacBook Pro. Try an SMC reset, maybe two or thee times.

https://support.apple.com/en-us/HT201295