The iPod played the last piece of music that had been selected when the battery failed. It played only that piece, it did repeat it, but then stopped, and I can't get it to play anything. The screen lights up with the selection - Music, photos etc, but I can't select them. Why would the click wheel have failed? It had been working until the battery swelled and then it wouldn't click.
Finally, got it open. The pry tools are useless; eventually careful use of a small jeweller's screwdriver forced the two parts of the case apart enough to get the pry tool in and work it round the sides. Two tips: the orange ribbon cable to the headphone jack was both stuck to the metal case, and held down by a piece of black plastic tape. This required care to remove, using a jeweller's tweezers. Second, it's not worth while unscrewing the circuit board to free the battery lead - just cut the wires and pull them through. The hardest part was re-attaching the ribbon cable connector for the jack. I used a paid of angled tweezers.