Aero turns itself off when you turn it on
If your Aero switches itself off almost as soon as you turn it on – sometimes turning back on and off again – this is usually the TV’s start-up behaviour rather than a fault. If the TV was off, you might also see the TV come on and then go straight back off.
(If the Aero instead switches itself off after it’s been running for a while, that’s a different setting – see Aero goes to standby on its own.)
When the Aero wakes, it uses HDMI-CEC to wake the TV and select its input. Some TVs are set to open their own home screen at switch-on, and as they start up they take over as the active input. The Aero reads that as a signal that another device has taken over, and puts itself back into standby.
Samsung TVs
This is most common on Samsung TVs. To fix it, on the TV go to Settings → All Settings → Advanced Features → Start Screen Options and turn off Start with Smart Hub Home. The TV will then start on the last input used, and the Aero will stay on – with all the HDMI-CEC features still working.
The setting’s name varies between Samsung models and software versions. On older Samsung TVs it’s Settings → General → Smart Features → Autorun Smart Hub. If you don’t see either, look for a Smart Hub auto-launch option in the TV’s start screen settings.
Other TVs
Other brands have similar start-screen options: if your TV opens its own home screen or menu at switch-on, look for the setting that makes it start on the last-used input instead.
You can also avoid the problem by turning the Aero on from the TV’s side: switch the TV to the Aero’s input, and the Aero will wake and stay on.
If none of this matches what you’re seeing, work through HDMI-CEC isn’t working for the general HDMI-CEC checks.