i figured out that on the gnx3 you have to first erase all of the internal memory from the factory before recording. but i still cant get the guitar track to record. it records the built in drum machine but not my guitar. it should play right thru my amp, right? i double checked and i am in record mode. all the buttons light up with the right colors like it says in the manual but still no good. can anyone walk me thru this? help....please.