I have a Sony DVD recorder, last night I pressed the appropriate button on the remote to bring up the programme list, and only got a blue screen, it is also the same when I press the button to see what is on the hard drive.
If it's connected to your TV via AV socket, go into TV Menu and press AV1, AV2 depending which one is associated with your Recorder. You may have pressed something on your remote without realising it.