Like everyone else I too have had fun with the Sony radio.
What I will try to explain is on the Sony CDX-CA720X-700X AND 705M radios. Some of us may have the XA-300 AUX-IN Selector also. There is a card remote commander RM-X118 also to control radio while traveling down the road.
The Source button will get you to (Power on/Radio/CD/MD) to select the source.
Once you hit the source you want you than press the MODE button just at 11 o'clock of source.
If you selected the radio mode will walk thru 3 FM and 2 AM bands of 6 stations each.
If your parked or before you leave you can select these 6 stations on 1 band by using the BTM- best tuning memory- button and it will select the strongest stations in your area. I wouldn't try while traveling down the road.
If you select CD/MP3 mode you will be connected thru the XA-300 AUX-IN Selector which is located under dash area on shelf and held on by velcro, you can lift fuse access cover on dash in front of your steering wheel and see it just to right of opening.
This unit will send radio input to a 10 or 6 CD/MD Changer, DVD Player,MD Walkman and USB input for MP3 source.
My TV is played thru the CD 2 AUX-1 input if this is what is displayed on your screen "CharlieM" it maybe why your not getting any sound from radio.
All these sources will have to be wired thru AUX unit, your laptop can store music and play thru USB port, I have been looking at some MP3 units
for music source instead of CD/MD units because they are so small.
There is alot more that can be covered at least I hope this will get you into the different sources that you may have off these radios.