Hello! I have some troubles with my iPod 30g. It's not charging.

The fact that it runs off the adapter, but has problems when connect to the computer indicates to me that maybe the connection to the computer is not providing sufficient power. That would also explain why it does not charge, despite a new battery.

As a test, I would shut down (power off) the computer. Disconnect all USB peripheral devices, including any hub. Start up computer with nothing connected, except a standard keyboard and mouse (if used). Run iTunes. Then connect the iPod to a direct USB port on computer.

If that works, you should probably do a Restore in iTunes from the iPod's Summary tab. Because of the problems you described when running off the power adapter, it probably needs a Restore, which will erase the iPod, re-install its software, and set it to default settings.

If you are using the same USB docking cable with the power adapter, the cable is probably OK. But if the power adapter has a different USB docking cable, try using that USB docking cable on the computer.

Yes, that's true... Maybe it has a battery problem (or a problem with the internal part that charges the battery). But since it does not seem to run quite right, even when connected to the power adapter, there could be some software corruption issue (on iPod) preventing the battery from charging properly. If it's a software issue (and not hardware), a Restore should resolve it.

If it's only a battery problem, then it should also work similarly (to using the power adapter), when it is connected to power from the computer. That's why I suggested the possibility that the power from the computer connection is not sufficient for some reason. Making the iPod the only high-power USB device on the computer's USB bus may make it work, if that is the cause.

tried 2 cables and another PC and still the same

Well, that might prove my "theory" to be wrong. 🙂 I think you should still try the proposed test.

You said earlier (when connecting iPod to computer)

comp does not react in any way

but is the iPod seen by Windows, when you connect it to the computer with iTunes NOT running? So does it appear as a storage device, or in device manager?

If you can get it to appear as a USB storage device to Windows, even if iTunes does not recognize it, you may be able to try a few other things. You can also try putting the iPod into Disk Mode (while connected to computer)

http://support.apple.com/kb/HT1363

to see if that makes a difference in getting the iPod recognized in some way by the system.

If you can't get the computer to see the iPod in any way, I think you may have run out of things to try.