Why don't my play and back buttons work?

I have some experience working with click wheels and here's my guess: The plastic menu button on the front of the ipod is not properly fitted over the metal disks underneath it. I've had times where I put the plastic piece on wrong and all of a sudden there is no click sound or tension when I press a button - it just feels stiff and wrong.

To remove the click wheel, take something very thin and strong - I use a fingernail (be wary of scratching the ipod casing with metal parts), and pry up under the clickwheel toward the center until it lifts up. Be careful about the area near 9 'o clock as there is a ribbon cable leading to the logic board and you don't want to damage it.

Also make sure that the click wheel is connected to the logic board. Just press your finger where the ribbon cable meets the ipod and make sure it is well-connected.