Audio Systems: newClarion no sound, clarion head units, watt speakers

Question
I purchased a new ClarionDB 245 for my son's car I had it installed by an experienced technician with four new Pyle 5.25" 120 watt speakers. The installation took several hours since the car had no factory unit  when new. a slight pop is audible when the power is turned on  but that is all. when a cd is inserted the display reads "NO CD" and the radio doesn't play either. They didn't ground the housing and I am wionering ifthis would cause this problem
Thank You.
Steve

Answer
Steve,

 the "POP" you hear is somewhat normal but most likly found in lower quality units that dont have the "soft turn on function" *this also applys to amplifiers*, now the unit functions , powers up ect.. so i dont think its a ground problem or else the unit wouldnt power up or function, the best thing is to take it back to the install shop and tell them it doenst work and you want it fixed , if you paid for the service its your right to return it, if you didnt and it was as a favor stick around and try to help them find out what is wrong , also give clarion a call or email to see if they have any information that is specific to clarion head units .. hope this helps you out if you need anything else let me know

thanks