Unsupported signal please check the device output mac sony bravia

sony bravia says unsupported signal.please check the device output I've restarted everything ...does same thing with iMac and macbookpro.....just trying to use sony as monitor

and......

connection cable used?
display settings on pc?
other relevant information?

i know for a fact that sony tvs work with pcs via a dvi to hdmi cable.

are you trying to use the displayport or whatever it is called jack on the back? if so then perhaps that is why you are getting the error.

in order to help you... you need to give as much information as you can.

i also take it that the tv works fine with all non apple products you have?