Toshiba VTV1403 NTSC Problem?

Hi,

I bought this TV (Toshiba VTV1403), about a year ago now. One of its features is NTSC playback. This feature was working fine when I first got it. I was able to play NTSC videos, and it was able to show any NTSC game (from my GameCube) in colour.

But a few months ago, the NTSC playback feature stopped working. I would try to play a NTSC game, but it would be showed in black and white, whereas before, with the same game, it was shown in colour.

I was wondering has anyone else had this problem with their TV, and is there anyone who can help me fix this problem please?

Thanks.