Hi all. It took some time, but I finally opened the package that finally arrived today with my A1200 and some games

Some of the game boxes are crushed, but everything else seems ok. But:
When I connect it to my plasma (Pananasonic PV60), regardless of scart port, the screen just goes grayish white. Kind of looks like the signal comes from the Amiga though, but nothing happens so I don´t really know.
The Amiga came with something that looks like a home made cable that I put into the wide, serial-looking port marked "video" on the amiga. Any thoughts on troubleshooting?
Ps. At the end of the cable, near the scart plug, it also has an additional wire sticking out, ending with two audio plugs of the regular kind. Is there any sound coming through the video port anyways? Seems weird. Tried to put the cables into the red/white audio input on my tv after switching on the power, but only got a weird sound that got louder and louder, even if I turned off the power from the Amiga.