Does the 2G iPod work? Does it charge? Have you tried to resettht eiPod to see if that will make it visible in iTunes?
Reset iPod touch: Press and hold the On/Off Sleep/Wake button and the Home
button at the same time for at least ten seconds, until the Apple logo appears.
Next see if placing the iPodi n recovery mode wiull make it visible iniTunes. For recovery mode see: