My computer has developed static in the sound. I replaced the speakers, without helping. Should I assume the sound card is bad, and if so, is it something I can change out myself?
Could you explain better the "static"? Does it seem to be related to, for example, moving the cursor, typing, or the hard-disk accessing? Or is it a constant noise? Have you tried changing the connecting cable between the computer and speakers? Or simply "jiggling" it? Have you recently re-positioned anything (especially if it involved unplugging and replugging the computer and speakers, ESPECIALLY if you re-oriented how they're plugged in (E.g. moved outlets, power strips, etc)). Does the static noise increase or decrease in volume if you adjust the volume controls on the computer (e.g. in Windows)? Or the volume controls on the speakers themselves?
Moving away from the computer as the cause, do the speakers produce static noise if the computer is powered off? If so, does it change as you adjust the volume level on the speakers? Have you tried moving the speakers to another room in your house (ideally on another circuit from your power box), does it have any effect?
Have you recently added or changed any major electrical devices in your house, like air conditioners, refrigerators, clothes dryers, whole-house vacuum system, light dimmer switches, etc? Have you recently added anything, especially near to the computer and its speakers, that uses wireless signals to communicate? (like a cellphone, WiFi router, wireless keyboard/mouse, CB radio, walkie-talkies, etc)
I know this sounds like a long list, but we have to narrow down where the noise is originating from in order to better figure out how to address it. So that's where these kinds of questions are coming from.