Radeon 4770 causing speaker interference

[beastyben1]

Hello:

System:
ASRock 870 Extreme 3 w/ Sempron 140 unlocked, 2.7ghz
Asus Radeon 4770 - the race car design h/s fan
Samsung 1TB
Win7 Ultimate
Crappy Dell speakers
Antec True Power New 550W

The problem: massive interference in my speakers with the 4770 plugged in. Piercing noise so no computer initiated noise even gets through it. Zero problem with Radeon 5770 plugged in (no longer have this). Using the integrated Realtek sound with newest drivers from Realtek.

Side information: this pc did cause my router to kick off the other wireless laptops, had to change channels. Tried different speakers to no avail. Tried the front port and the rear jack using just analog to no avail.

Could a cheapie sound card fix this? I've tried moving the pc power plug to a different outlet, everything has a surge protector but this doesn't work. Unplugged the router and this still occurs. Even unplugged the 4770 fan but it didn't work.

Thanks for any input.

 

[Jen]

may want to state what powersupply you have as well

Jen

 

[beastyben1]

Oops. I forgot, Antec True Power New 550W

 

[beastyben1]

I just added a 6870 and the noise still persists. I unplugged the speakers and just did headphones to the rear of the mobo and I got nothing. Nothing from the front panel either. I installed the latest Realtek drivers, then went back to default Windows and nothing. I was working fine with the 5770. If I install the Dell speakers and crank up the volume control on the speakers I'll get that interference but no sound from the pc.

The power supply is from an RMA to Antec. It has a slight pulsating hum to it.

So I can only think to reinstall Windows, RMA psu, or RMA mobo.