2005 G35 Car won't start please help
 

My car is a 2005 G35 Coupe.

It's currently at 59xxx Miles.

While I was driving the car the power just drop from 5RPM to 0 so I automatically pulled over to the side and try to start the car again and it doesn't seem to work. I thought maybe the battery is dead and need a new replacement which I immediately got a new one to replace but then it doesnt seem to help when I try to turn on the key it would go like half way but it would not start so I had it towed to my family's mechanic to check out the car for me as we go thru the problems, checked the starter and the battery both of them seem to be working perfectly fine however the car would not start..

Another problem is that when we take out the key we would hear some weird noises behind the radio. have anyone ever had this problem? What need to be done?...