Isolating a specific problem

Carlin, If your iPod does not charge the battery, or if it says "Battery Low" Start with that problem. Check the dock connector for any bend, broken, or corroded pins. Clean it with some isopropyl alcohol and some compressed air. See if that makes a difference. You also want to try cto charge your iPod on an AC wall charger. reason for that is that a computer USB port may not supply enough power to charge a battery that is discharged below its threshold. If that does not work, replace the battery. Follow this guide and the battery is available here iPod Video 30 GB Battery as well as many other places. Watch the battery connector when you remove the cable, it does have the tendency to break of the board if you do not pull the clip straight up. When you replace the battery, make sure the cable is inserted up to the marking on the cable. See if that makes a difference. If it still does not charge, you may have problems with the IC on the logic board. Check it for any damaged (overheated) IC's as well as missing SMD components.

then you still have the hard drive issue. I would go ahead and replace it as well. The drives are easy to change and not very expensive. Here is the guide for that. You can of course get the hard drive from here and you can also check for parts here. the total cost of this will only be a fraction of what a new iPOD will cost you, and well worth the repair. Hope this helsp, good luck.