I think we have a ground loop
Had a problem with a projector for months, ever since I started here, the image from the PC has a constant flicker.
Tried running a new cable, a new VGA splitter, tried a new PC, and none worked. I knew it wasnt the projector because connecting it to my laptop worked fine.
So after reading a random thread on here the other day about ground loops causing interference, I tried plugging the projector in to the same wall point as the other equipment is plugged into - and voila the flickering is gone!
I also tried with other power sockets round the room but they seem to induce flicker too, only the one with the PC/splitter connected to it works.
So what do I do? I could run a load of extension leads and plug the projector in by the PC rather than on the ceiling. But that would look a bit messy.
Or is there something an electrician can do? We have a regular one, who I assume fitted the sockets in the first place, what would I need to ask him for?