Building a MAME cabinet

Although I've known about MAME for many years, I've just now started to
think about building my own cabinet. I'm using xmame (I run Linux) and
all works well, but I'm having problems getting the TV out of my nVidia
Geforce4 MX4000 video card to work on my "older" Sanyo 27" TV. Perhaps
it's because I don't have a SVIDEO-to-RCA converter (my video card has
SVIDEO out but my TV has RCA in) and made one myself using the following
schematic (which should work, btw):

RCA SVIDEO

---------- 1
gnd ---------|
---------- 2

---------- 3
data --------|
----||---- 4
470pF

The SVIDEO pinout (for more, see http://en.wikipedia.org/wiki/S-Video):

####

1 O O 2

3 O O 4

Anyone have any suggestions? Thanks!

--stridex