How can I get my Sat/DVD to come through my Hitachi UT42mx70?

I have brought a Hitachi UT42MX70 on 04/05/2009 and have connected it up as to the manual. It came with a separate digital Reciever box (HDB73) to which all external scart leads go into and a single HDMI lead goes to the TV. However, even though I have connected the scart lead to the VCR/AUX connection (as directed), all I get when I switch on the Cable/DVD player is a blank screen on the TV and no sound.
Please can you help me get the Cable/DVD player to work with the TV?