Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!cica!tut.cis.ohio-state.edu!pt.cs.cmu.edu!rochester!rit!tropix!moscom!ur-valhalla!uhura.cc.rochester.edu!sunybcs!rutgers!cs.utexas.edu!uunet!portal!cup.portal.com!mmm From: mmm@cup.portal.com (Mark Robert Thorson) Newsgroups: sci.electronics Subject: Re: Looking for vibration-noise abatement product Message-ID: <19589@cup.portal.com> Date: 22 Jul 89 00:31:18 GMT References: <25538@agate.BERKELEY.EDU> Organization: The Portal System (TM) Lines: 17 My dad used to have a TV repair business in Palo Alto. He once was called to fix a set that was making a high-pitched whine. Even back then, my dad's high-frequency hearing wasn't too good, so he couldn't hear the noise the lady was complaining about. He took off the back of the set and found that there was a Coke bottle back there. He figured the noise was coming from the high voltage rectifier section (this was 30 years ago, before TV's had silicon diodes), so he shoved the Coke bottle in among the tubes there. The lady said that fixed the problem! I would guess that your problem is a bit similar. You might see if you can shove one or more toothpicks between the secondary of the flyback and the flyback's core. The toroids are probably mounted horizontally with a bolt through the center, so maybe you can tighten the bolt (or shove in more tooth picks). You say the toroids are in your EMI filter and surge suppressor? Then they shouldn't be buzzing. You'd have to have a lot of EMI to make one of those toroids flinch. Are you sure you aren't looking at your DC power supply? Lots of switching power supplies produce irritating buzzes.