After opening my classic 6th gen 80gb iPod classic a few times, I've found that the menu button doesn't work. It was working before with the click wheel that was a little wonky, but having replaced the click wheel with a new one, the previous problem disappeared only to be replaced by a different one with the menu button.
All the other functionalities of the click wheel work: rotation, pause, forward and backward, center button, but the menu button doesn't work.
This means I can't reset it or get it into diagnostic mode (as far as I can tell).
What can I do in this scenario?