Bought the new playstation3 that is backward compatible. Bought the grinder guitar and guitar hero ii for playstation 2. Plugged in the grinder and it syncs beautifully and I can move through the main menu of the playstation using it as a controller. Once I put in GHII, the guitar lights flash then go out and it doesn't work. The grinder is compatible with ps2 and ps3 and is supposed to work. Tried the troubleshooting available but it still doesn't work once the game is in.

If you bought it new call Activision, maybe they can help. However your problem might be that the guitar controller is not PS3 conpatible, the PS3 software is compatible but it sounds like the hardware is not.