Black and White

[Silverhawk]

I'm as new as a newbie can get, and don't really know much about electronics, but I was wondering if any of you guys could give me a hand...
I have a PSX connected to a Phillips VCR and TV, which are both PAL/NTSC compatible. I was playing one day, and it was fine, but after a while, it ####ted flashing to grey scale and back. Now, on that TV and VCR, it stays grey, occasionally with a flash of colour. Now, I have another PAL/NTSC TV and it works fine on that. People have told me that this problem doesn't usually arise on PSX, but on PS2. I completely at a loss what to do, and I've already tried everything I could think of... Are there any suggestions?
By the way, all games played have the same problems, originals and backups alike. My playstation is PAL, and I'm using it with the cables they were supplied with.
I would appreciate any suggestions.