Simple fix for the scd 777es "no disc" message?

Try cleaning the lens w/q-tips and windex. I experienced the same problem a while back and after searching the archives at Audio Asylum, found several recommending the lens cleaning. You should be careful when doing this and not use a lot of pressure because the lens scratch easily. Simply remove the top cover (you will have to unplug a small wire harness going to the motor for the sliding door) and the lens and sled and motor, etc. will be apparent. Clean the lens and reassemble. Also the contributor reported that the sony serviceman told him the the felt on the bottom side of the stablizer was a major source of dirt and dust. To prevent tracking dust into the machine from the felt, he recommended to always place the stablizer brass side down on a clean surface when changing a disc. Also he recommended using compressed air to spray clean the lens periodically to remove dust.

After cleaning my lens approx a year ago, I have not experienced this problem again (knock on wood).

Good luck

On a Denon 2900, when I play one type of disc (CD, SACD, DVD-A) following another of a different type I sometimes get a hangup, and a "No Disc" message.. It's as if the player was still looking for the prior type of disc. (This NEVER occurs with my less-expensive Pioneer). Opening and closing the drawer always clears the problem. Disc cleanliness has nothing to do with it.