What is the make/model of the adapters? Most powerline adapters have lights indicating 1)connection to other adapters and 2)configuraton to LAN. This will give you a valuable clue to where the problem lies.
The Sony BD player may need to be configured for a wired connection as well.
Do you see any error messages when attempting to connect?
I am trying to connect a sony blu-ray player to the internet using a powerline adapter but the BR player does not connect. I currently have two Satellite DVR receivers using the same powerlines and they work fine, but the Sony player does not connect to the network. I have to try a wired connection because my wireless signal to the player has trouble with netflix and other download services. Connection gets lost.