Using an S-Video Cable for ADB

You may think that you can use an S-Video cable to connect an ADB keyboard, however this may not always work because pins 2 and 1 are connected together on some (but not all) S-Video cables, as they are the chrominance and luminance grounds, but must be separate on ADB because they are the soft power switch and data signals. If you are using an S-Video cable as an ADB keyboard and the keyboard doesn't work or the computer doesn't POST, this is probably why. Tying the Y/C grounds together is wrong for S-Video as well and can cause interference/poor video quality but it was done on cheap cables to save money on wire.