It may that your T.V is puting Blue ray on hd channel or that your ps3 blueray is not working. What I would do is play your blue ray and after it loads see if your ps3 is still on then check other channals by pressing the T.V/video input or the source button. see if it come up. if it does'nt I would say the ps3 blue ray is not working.

hope this helps.