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Traveling horizontal lines on a projector display? Answered

I hooked up this projector at work (it's a BenQ) and when I view the projected image (in this case a computer screen) I see horizontal lines traveling up the picture.

This projector is the only thing on the circuit right now.  I had to branch off the existing electrical line to add a new plug on the ceiling.  When I plug the projector into the existing outlets I get no lines, when I plug it into the outlet I installed I get lines.  The existing outlets on the circuit are all isolated grounds.  I have tried wiring in a regular outlet and then switched it to an isolated ground when the lines appeared, thinking it could be a ground issue.  I know my wiring is correct as I've installed these projectors before.

What could it be?


Noise injected from the supply ? RF from a dimmer circuit ? I bet its picking UP RF off the "isolated" ground wire !

Tried a power line conditioning brick ?

Well, if every outlet on the circuit is sharing the same isolated ground wire, why would I get lines when using one outlet and not the other?

RF is a funny thing, is all I can say. Did you try a filter ?

Nah, I haven't tried a filter. Thanks for your advice!