Hi, This is my first post, I have an HP pavilion ZD 8157ea power supply problem.
I use my laptop for stage work/ multimedia ie music through power amplifiers, when I use laptop without the mains power supply, everything is great. When I plug in the power supply I get a high frequency electronic noise not loud but very annoying.
I am led to believe that this is a common problem with the new style power supplies as they are not suppressed, my question is what can I do about the problem, is there a solution, where can I get a suitable power supply that will not cause this problem.
Thanks for any assistance

I use my laptop for stage work/ multimedia ie music through power amplifiers, when I use laptop without the mains power supply, everything is great. When I plug in the power supply I get a high frequency electronic noise not loud but very annoying.
I am led to believe that this is a common problem with the new style power supplies as they are not suppressed, my question is what can I do about the problem, is there a solution, where can I get a suitable power supply that will not cause this problem.
Thanks for any assistance