My tv won't display my dvd home cinema system?

[LloydCarter]

My tv won't display my dvd home cinema system when connected via HDMI, the tv is Toshiba and the home cinema system is samsung., but when using a scartlead the display works fine but is such a poor quality picture i used to have the system working fine, but when i test the dvd play down stairs with all the same cables and things with the hdmi cable, but with a samsung tv the dvd play works fine i really a stuck with what to do please help