hum from external speakers (line out) when using external display

[ashjamben]

i'm hoping someone can help me out on this little problem

my usual set up is a pair of speakers connected with jacks via an m-audio usb audio interface, with an external monitor connected via mini-dvi to dvi.

now for some reason my audio interface has randomly broken (on a side note, could a power cut have somehow broken a usb peripheral connected to my macbook whilst it was asleep?) so i've hooked up my speakers to the line out to rca. Now for some reason, when i plug the mini dvi connector into my macbook i get an incredible amount of hum. not just a little, alot!

does anyone know why this is? and how i can get rid of it?

it doesn't do it when i use the line out with headphones, so maybe something to do with it being rca? it still doesn't make much sense, it's as if plugging in the mini dvi it creating some kind of link to the line out. really strange

any help would be great, thanks

 

[techound1]

Try connecting the speakers to a known good power strip; one that has surge protection and/or noise cancelling capability would be ideal, and then, plug this into the outlet that you have the MB connected to.