I have Cyrus Quattro very similar to dAD3. It did not recognise any CDs but after cleaning the laser it does now. However it skips the track here and there for a part of a second. It does not mute and doesn't make the usual click sound - just small part of the sound gets missing. Is this rather laser(digital) problem or mechanical? My Cyrus dAD1 I am working on still has serious dried grease problem. So maybe this Quattro that shares the same transporter model has it too.