Extremely loud hum/buzzing from speakers

I would check the caps on the power supply. They are rather large electrolytic capacitors that will look like they burst and/or leaking. When these die, the caps ground and the sub will make a loud buzzing sound. If you are handy with a soldering iron you can replace them yourself. Replace them with the same voltage or a little bigger and same with the size.

If the cap. says 16v 4700pF on it, for example, a 20v 5300pF or a 16v 6200mF cap. will work for this application.

They sure do. In fact, they should work with every operating system on any computer which has an audio out jack.

how to connect bose 5.1 to mixers

A lound buzzing sound is an indication that the Driver (transistor) for the amplifier final is bad. This is not so much a buzzing and it is extreme in loundness.

I just found one in my basement.
HK195-01T 120VAC.15VAC @ 60 hz 22Watts.
Contact [email protected]

Select Start > (right click) My Computer > Manage
In the Management window select > Device Manager
Next to Sound, Video and Game Controllers click the + sign
A yellow triangle will signify a problem so if one is present, right-click that device and select Properties
You can then choose to update the driver
For more details check Dell Xps 420 Manual.
Dell Xps 420 Manual

Hey, I was in the same situation. I tried a 9V DC (yes DC) converter I had and it works perfect. You can use a DC on a AC input - never the other way around. Due to insufficient power I get distortion at very high volumes... but I never play that high so I'm good..

I have sort of the same problem...there was a loud snap(kind of electical spark like) then the unit started humming loudly which changes sound as you move the unit around. The picture remains clear and the fan is quiet in shut down mode...still the wheel you think?

you need do :
1) make sure the speaker system works ok,
please reference here to make sure your speaker connection.
http://support.dell.com/support/edocs/acc/hk195/Notes.htm
power on then touch the male jack by your finger, heard noise which is works well then go next
2) to make sure whats the PC speaker outlet hole, then put the male jack to your PC.
hope help you do it well.

Please try moving the laptop to another location, if you have not already tried that, especially if you have any other electromagnetic device nearby (like a transformer, motorized device, machinery, etc...)