Amiga RGB to S Video & composite adapter

[Chartus]

I built this from a schematic I saw over on the English Amiga Board.  I wanted to get S video working on my 600 and 500.  The problem is that S video doesn't work.  A brief flash of a garbled Workbench screen and then the screen goes black.  Same thing on both computers.  Composite works fine.  Anyone have any ideas about what might be going wrong with it.

Links are below.

eab.abime.net/showthread.php?t=30752

www3.telus.net/narmi/schematic.png

[Chartus]

Yes I know.  Its mostly for the old Amiga 500 that I have.  I wonder if it is a bad cap going to the s video port?  Colors look good coming out of the composite so That means that the RGB inputs are working. (I think)

[Chartus]

Read your post and switched the outputs.  I was in a hurry so I used jumpers to switch them. Pulled the cable from the TV to run a quick check. OK everythings connected again.  Pluged it in the 500 and turned the computer on.   .....Nothing.....oops..... I neglected to plug the s video cable back in the TV.  Powered everything down and plugged it in and  IT WORKS.  It's time to heat up the soldering iron.  

I went back to the ADF for the AD724 chip and if I am reading it right they have the schematics wrong for that part of the circuit.

Thanks Wingnut.