DDJ SR2 NO SOUND

Ensure that the channel trim / gain knobs and master knob are such that signal shows on the meters, and that the channel faders are up.

hello , after i connect my ddj sr 2 , i always face an issue regularly with no sound output, its really strange , i have output on my headphones , the led lights on the controller show output , but no sound output on my p a , sometimes it just works fine after i connect , its like a ghost in my machine , i am using a mac book pro late 2011 4 gb ram with latest updated version of mac os sierra 10.13.5 , sometimes when i crank up the master volume of my sr2  the output on my p a suddenly starts 

@Senthil > It could be the software isn't recognizing the position of the knob until it's moved for the first time. Which version of Serato DJ / Pro are you running?

hello, i just bought the ddj sr2, thers  no sound the master lights are dark 

theres no sound coming out of the PA neither of the head phones can you please help? 

i already tried everything.  

@tiago > Did you install the drivers? If using a Mac, did you follow the instructions to bypass the driver security?

i just got a new mac, is big sur version 11.3 when i connect my ddj-sr2 on the bottom of the screen it shows, "failed to connect audio. can some help? 

the lights come on but non of bottoms work.

@Wilder > Did you also follow the instructions above? If you have an M1, you also need to follow the instructions here.