My Tv picture going black/white when on scart?

My Tv is a Bush 6690d AK17, it has built in on digital, which now runs freeview. On the back it has 1 scart socket, which sadly now, everytime i run something through it, the picture comes out black and white. I used to run my dvd player through it, but now am trying to use it for BT Vision. With my dvd using the yellow, red, white 3 pin socket thing on the side of the tv. Ive had the back of the tv off but cant see anything much as i dont know what im doing. It looks like it has a a digi box built in, with scart leads running from that to the tv board. Ive uploaded some picture. Thanks for any help.
http://img503.imageshack.us/img503/9154/dsc00046pe5.jpg
http://img80.imageshack.us/img80/3365/dsc00047po9.jpg
http://img216.imageshack.us/img216/7048/dsc00048ap3.jpg
http://img216.imageshack.us/img216/7729/dsc00049yv0.jpg
http://img80.imageshack.us/img80/7082/dsc00050zu8.jpg

Damian
September 2007