I use my laptop as desktop, run a monitor on it and speakers etc... anyways when I plug it in it causes interference in the monitor and sound. Anyone know what causes this?? And how to remedy the problem.
The interference is probably coming from the higher voltage power wire... EMI. Make sure that the wire for the power supply doesn't run parallel with either the audio or monitor cable and try to separate them as much as possible. For the audio cable you can purchase a ferrite toroid to get rid of some of the interference in case you have trouble keeping them separated.
You'll loop the speaker wire around the toroid like so... more loops for greater interference...
The best place to get them is from old junk PC power supplies... can't beat them for free! That's where I've gotten mine at least.
Hmm, are there any modifications that I can make to the power supply EMI? Its mostly the interference it causes in my monitor that bothers me.
Wasnt the interference problem a factor when they decided to use this type of power system?
EMI stands for electromagnetic interference. The most typical problem I've run into like that is when people install an amp in a car and they make the mistake of running the power wire along the same side as the audio signal wire. When they're routed that close together like that, they end up making the rear speaker emit an audible hum that increases in frequency with the engine RPMs... pretty annoying.
An option for the monitor cable would be to get a roll of EMI shielding tape and wrap the monitor cable with it. It sounds like the monitor output is very close to the power plug which is unusual... for the reasons your experiencing.
What model is your laptop?