Chosen Solution
When I plug in my headphones my IPod Classic does not play in stereo.
That is a common problem with all the classic style iPods. 90% of the time it’s just he jack that needs replaced. Over time the contacts inside the jack just wear out. There is a guide here how to do it: iPod Classic Headphone Jack & Hold Switch Replacement The exact part you’ll need will depend on exactly which model you have. Some were thinner than others. Part for the “Thin” Model: iPod Classic (Thin) Headphone Jack & Hold Switch Part for the “Thick Model: iPod Classic (Thick) Headphone Jack & Hold Switch
