my headunit freeze when starting car

this is not big brand headunit issue..

i got this poweracoustik razr looking headunit.

i put key in and headunit turns on and playing music or whatever..then i start my car, sound is not coming out...i have to press source button and it works..

is there any way i can solve this problem??

i tried putting acc wire to constant 12v wire and still doing same thing..

could this be defective from manufacture??

it plays but no sound until i press source button..could this be MOSFET amp inside is defective???

help me on this please..

too much hassle to send defective unit out and wait for couple weeks.sigh..

i will have to turn it on and off manually when i get in and out of my car..