Why does it not turn on? Original iPod click wheel 4th Gen monochrome

Why does it not turn on? Original iPod click wheel 4th Gen monochrome
My very old iPod no longer powers up at all when plugged in to a socket or computer or a dock. I suspect the batteries have died. Also the click wheel no longer 'Clicks'. Only one side of the wheel clicks and so (when it was working) sets of random commands.

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