hdmi connections

new to this so please excuse if posted in wrong place -

can anyone explain the following -
been helping one of my friends selecting a dvd player to use with her modern lg tv , after using it for a week on scart connection everthing was fine , bought a htmi cable connected up , would not work . took the unit to my house wouldn't work even with my own working cable, with exception of a little sound and remarks of out of range . so i took the item back to the shop and they tried it on 2 tvs with and with out my cable , worked both times . but dicided to change dvd player for a different make , that worked first time . i am puzzled . the first player was an Lg the latter a Sony . My friend is now quite happy but i would like to know why .

regards peterfaldo

HDMI, HDCP handshake issue. It matters not the brand if they (2 pieces of equipment) don't communicate properly. The handshake negotiation does change. In some cases a simple firmware update to the player or TV is all that is needed to correct these issues.