I have a 2006 Altima 3.5SL with Bose radio. The radio just stopped working, no lights or clock at all. I checked and replaced both fuses in cabin and underhood. just to be certain, but radio is still not operating. Everything else is working perfectly in the car. I also changed the radio with another that has the same reference number, but the replacementdid not power up either. any helpwould be appreciated.

Welcome to NICO! First thing to check would be power going to the unit..

http://www.nicoclub.com/FSM/Altima/2006/av.pdf

If the unit itself is not powering up it would also not power up the bose amp.. So I'd check to see if you have 12V between the Yellow/green wire and body ground, key does not have to be on. If you don't then you know its not getting power at all and you'll have to trace it back. Next would be to see if you have power when the key is on between the purple wire and ground, which should only have power when the key is on. Report back with your findings!