My ipod classic died again the other day, after being alternately frozen and baked in my car for several months. I don't believe in coddling my appliances.
I tried the frozen ipod reset trick, and recharged it overnight, but nothing helped. All that appeared on it's tiny screen was a "Battery Charging" icon or the "Sad iPod" face with Apple's iPod support URL below it.
Would I be able to fix it this time? (see this post for what I did last time it stopped working)
I spent about 20 minutes trying different implements to attempt to crack open the case. I found that the best tool is a utility knife. It has a big handle, so it makes it easier to control, and the blade has a very thin edge, which can be carefully worked in between the upper and lower casing. Work slowly and carefully and use a bright light to see what you are doing, because the knife can slip. A dull blade may be best, because you are just using it to pry, not to cut.
Once I found a spot where the knife actually slid through the gap between the casings a little, the ipod came right back on. It seems that the case must have warped from the temperature changes in the car and stopped the hard drive from spinning. Forcing open the case slightly apparently released the pressure.