Wi-Fi networking issues with Apple TV; getting IP address

Hi,

I have an Apple TV 1st generation. Since I bought it, I have some troubles to associate it with Wi-Fi network.

I use to turn off my wireless router when I don't need it; I changed in these years 3 wireless router and I have also an AirPort Extreme.

I noticed Apple TV works fine after the wireless setup till when I turn off the wireless router. When I turn on it again, I have to setup again AppleTV or re-start it to see Apple TV back in my network.

It seems it looses connectivity when I turn off the router and when it turns on again there's the wireless association but the IP address from DHCP is not acquired, it still remains 169.X.Y.Z.

I tried to setup my router with a DHCP with address reservation or configure Apple TV with static IP address but I stille have same behaviour.

If I don't configure DHCP with my subnet, my stations in network have the default IP address (169.X.Y.Z with 255.255.0.0 subnet mask) and in these way, Apple TV can be reached but of course I don't go on Internet (because DNS, gateway, ..., are not set correctly).

As I said, if I don't touch anything but just restart my Apple TV or set up again wireless connection (in the same way), everything works fine for days, till when I turn off again router.

How can I fix it?

Thank you.