how do I update the firmware on my older wireless apple keyboard?

Neither of my older apple wireless keyboards (I believe they are the aluminum kind, with the cylinder style at the top) work anymore with my Apple TV's. Is this because of a firmware issue, or has apple os made my older keyboards obsolete?

I also can't use them with my new iMac. In all instances, it recognizes them when in pairing mode but when you select to connect them it says "error' "make sure it's turned on and in range".

But, batteries are new, its on (or it wouldn't have been recognized in the first place) and is literally 1-2 feet from the Apple TV I'm trying to pair it with.

Anything hope for me? Is there anything I can try?

Or should I toss these two keyboards in the scrapyard?