My 2004 chevy blazer wont start after hooking up the radio, what happened?

How do i fix this, truck wont start and the dash lights are flashing, i waited 10 minutes and tried to start it but still nothing

put the old one back in,see what happens.if it starts and runs,take it to Best Buy,they will install the new one.

Put the old one back in and still nothing

Disconnect the negative battery terminal for about a minute,after taking the original radio back out(leave it unhooked for now) try to start it. is the theft light on steady or blinking? is it cranking and not starting? When you installed the radio, did you hook it straight to the wiring in the vehicle or did you install a communication adapter module? aftermarket radio?