I'm missing a colour channel. But which one?

Hi guys, I recently did a 60Hz mod on a console, but for some reason now the colours are now incorrectly displayed. I checked the traces and the solder in case something broke while I was working on it, but I couldn't find the problem.

So this is what is displayed, compared to an emulation screenshot:


Now the trick: the missing colour can be in either RGB or YUV colour space. The video chip outputs Y, R-Y, B-Y and it's then converted to RGBS via a daughter board, and displayed as RGB with Scart. There is no Composite output to compare it to.

What am I missing?

 

Where's the blue?

 

White seems to be correct, so the RGB stuff must be working as must the Y channel on the YUV side. My guess is that B-Y is missing.

 

Actually the white is now yellow, the white portion of the walls are exactly the same colour as the terrain. White becomes yellow, blue becomes brown is what I can tell. Everything seems slightly off but it may be the TV.

If B-Y doesn't show, then it might be a case of broken PPU, but I have no way to be sure without an oscilloscope.

 

The blue was indeed missing. A trace was broken next to the AV out socket.