it also depends on what kind of telly you have.
My black original atari 2600 hardly gave any picture on my tv box, yet the picture was very good for a 2600 that is) on my new samsung telly. Also, a rusty connector can be a cause.
If you´re really want the a2600 to be in absolutely original state you can deal with it laying the connector for a 2 days or so in cola. The sour of coke will dissolve the rust wich (probably) causes the bad picture.
