I'm using a lamp projector attached via VGA to a MacBook running OS X 10.6.
The problem that I'm experiencing is that the image is all green. How much green? Well, it looks like there is no red channel at all, but not quite macrovision-green.
The same hardware combination worked ok in the past, the only thing that has changed is that now I'm using a very long VGA cable (at least 20m/60ft I'd say).

I've tried every possible color setting on the two devices (including, but not limited to: recalibrating, choosing different “color modes” on the projector, changing channels luminosity values), so is the cable the only possible cause left?
Is it a broken cable, or is it just too long and the signal will degrade?


1 Answer 1


It definitely sounds like the cable and that you've got a break somewhere. If it was too long I'd expect to see a degradation in all colours not just one.

Can you check that the plugs are OK or is it all moulded plastic?

You could try to see if there's an electrical connection between each input and output pin, but you'd need a very fine tip on your circuit tester.

Have you contacted the cable supplier to see what they say?

  • Thank you for your answers. The plugs are molded, so no luck. The cable I'm using is not mine, I found it already installed on a location where I brought the hardware (it's a big hangar-like structure), that's why I don't know the exact length OR the conditions of the cable prior to my arrival. Unfortunately my tester will never fit in there, so I guess I'll have to make without until the cable is changed! Thanks again
    – Agos
    Dec 19, 2009 at 21:42

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