Laptop – Buzzing Problem

This may have been covered to death before but I don’t usually visit this board so my apologies In advance.

When DJ’ing using my Laptop which Is linked through my mixer etc by a standard 3.5mm – from the earphone out socket – to twin phono I get a buzzing sound through the speakers, one soloution I was told was to disconnect the earth wire Inside the power supplys socket – this I did and It cured the problem for 2 or 3 weeks, however the buzzing as returned (and I do use a circuit breaker at the main wall socket).

If whilst still linked up to the mixer etc I remove the power lead from the Laptop and let It run on Its Internal battery the buzz again goes away however naturally the battery begins to lose power.

Help ?

I bought the laptop – last one on the shelf from PC World In August – It came all boxed up with Its power supply unit etc etc.

Apparently this Is quite a common problem however we appear to have traced the problem to a ground / earth problem from the PSU and therefore I’ve ordered this http://www.vtx.co.uk/audio/pureformer.htm I’m told It should cure the problem.

Fingers crossed !