Have a philips ccr 600 with blaupunkt 6 cd changer?

where do i start,ok he we go ,i Have a philips ccr 600 with blaupunkt 6 cd changer put he code in for the radio that all works fine ,then i connected the cdc changer when connected it powers up and does its routine of running though the cd cartridge,the problem is trying to put the code in via the head unit,
this is what i do:

i turn off radio hold in cd button instead of as, on head set and turn back on,i dont let go untill u hear a beep ,and thats where the problem is i dont get a beep or a display to enter the code.

please can someone help me with this matter :(
regards
dan