Audio Systems: factory Chevrolet Tahoe Radio (2003), chevrolet tahoe, chevy dealer

Question
My factory radio had went out, so I bought another one but when I plugged it in it said (locked) on the display and nothing happens.

Answer
You must unlock it.  The manual that comes with the unit will have instructions on the locking codes.  If you do not have the manual you must contact the Chevy dealer or their agent for codes.  If it is the anti-theft code you must prove your ownership and pay a fee to get the unlocking code.  If you google search you can find some online providers that claim they can get the code for you but I have not tried them and cannot confirm their quality of service.  

If you are not talking about the anti-theft code let me know further.
C

PS:  http://www.radio-code.com/?gclid=CJXa4IymgpUCFSQtagodk2cZrQ  

is one such company that provides a code service.