Apple TV 3 HDMI difficulties

I have connected an Apple TV 3 via a HDMI faceplate (which is connected to an automatic switcher) and then to a projector's HDMI port.

When I start to power up the Apple TV3, the Apple logo appears on the screen followed by a spinning disk symbol until the Apple TV3 is fully powered on. When the device is on, nothing appears on the projector's screen. When I check my iPhone 5S or iPad Air the Airplay icon shows the Apple TV, you can select it, select mirroring option and the device asks you to input the Apple TV3 password but nothing appears on the projector's screen.

I have connected the Apple TV3 directly to the switcher and it works perfectly, i.e. image appears on the projector's screen.

Any ideas as to how to resolve this problem?

Thank you.

Regards,

Paul Murphy