Jbws2010

Recently purchased a 2010 MKS 3.7. When turning on the stereo it will show working in the display but no sound. I have used the Bluetooth and people can hear me but I can't hear them. Now here is the kicker. In about 10 - 15 minutes, everything comes on and sound is there and I can hear incoming calls and the THX sounds great. So then I turn the MKS off at my destination and it comes on when I restart. Then will go out for about 5-7 minutes then it's on and stays on as long as I keep it on . I've heard from some folks that a system reboot ( negative cable pulled off of the battery for 15 minutes ) will work in a 1 in 20 chance. I really don't want to do this. Is this wiring or module or amp or pre amp????? I'm lost on this one. I love the ride of the MKS.