Is this what you would be talking about Marty Machine? This is about all I could find that remotely helps or could remedy what you are talking about
If your PC does not sense your monitor it is likely your monitor is not loading the RGB signals. Measure input resistance from one video signal (R, G or B) to ground with an ohmmeter, in 200 ohm scale it should read around 75 ohm. Some monitors have a switch or jumper to enable loading of video signals, if yours does not have this setting you can add three 75 ohm resistors from each video signal to ground as shown below.
Yep, the diagram you provided is exactly what i meant.
Thanks Marty Machine, I guess I just splice into the vga cable with the resistors and earth them, fingers crossed this works
Trip down to jaycar tomorrow