Do I need to replace hard drive?

Recently placed my iPod on a slightly magnetized metal plate (a cover for a nook that I think was made magnetic due to the magnetic clasp). The iPod played for several minutes and then shut down. The symptoms are ,click wheel does not rotate,turns on when menu spot pressed. Apple logo comes up for several seconds and then the file folder icon comes on and then the iPod shuts down. I tried restore when connected to a MacBook Pro and the device was not recognized on the iTunes menu. I then tried pressing both the menu and center of wheel as recommended but does not help. The iPod did get warm when the problem first occurred. Any advice greatly appreciated.