BUZZING COILS whine whistling etc

ZenmasteR · Post by **ZenmasteR** » Mon Jun 09, 2003 11:26 am

recently I upgraded to the new 800FSB based intel P4 system,
At first I had an ABIT IC7G mobo with 3.0ghz cpu and some mushkin ddr memory.
PSU I tried at the time was a Enermax 431 watt version of the 465 range.
after couple of days of usage I noticed a strange patern, in 3dmark2003 cpu test1 I could hear buzzing or whining noise (coils??!) from the PSU
definitely not any fans. A month after and I have tried another IC7G mobo, an ASUS P4P800 mobo , another enermax 465 (460watt psu) and an ANTEC 550 TP psu, i've changed a whole bunch of components and still I have the NOISE!!!
it increases in noise when ambient room temp is high (29-30c +)
I have tried different cables, AC outlets (240v ac native).

I am at a wits end on this issue I need SALVATION!!

dukla2000 · Post by **dukla2000** » Mon Jun 09, 2003 11:34 am

ZenmasteR wrote:240v ac native

Are you EU (and/or are those PFC psus)? Go get yourself a non-PFC psu. A bit heretical, but in the last years I bought 3 PFC psus because "they were better". They all had electronic buzzing/humming that I couldn't sort despite variously trying rubber grommets, epoxy on an offending choke, thermal tape bound around a choke, wedging toothpicks and other blunt instruments in components to try stop the noise.

I now have a non-PFC psu that is electronically silent.

Post by **MikeC** » Mon Jun 09, 2003 11:40 am

ActivePFC PSUs do not seem to be prone to additional coil noise.

ZenmasteR · Post by **ZenmasteR** » Mon Jun 09, 2003 12:28 pm

dukla I c your from Berkshire

I'm from Slough

anyways which PSU did you get and isn't non PFC less effeicent?

MikeC, what do you mean by ActivePFC ?

Bat · Post by **Bat** » Mon Jun 09, 2003 12:32 pm

Active power factor correction, rather than passive. It's explained elsewhere on the site.

dukla2000 · Post by **dukla2000** » Mon Jun 09, 2003 2:18 pm

Actually, my initial response was a bit dogmatic. It may be worth trying to isolate other components that could be causing problems in the psu, as well as trying a few ferrite rings on power cables to things like your hard drives (I have read somewhere that worked for someone).

PFC is one of the 'good things' in life - as per Bat there are better descriptions in some of the other threads and in Mike's psu reviews. I am not clear whether it is more efficient for my electricity bill or my environment, but that is not the point. There are active (needs a bit of a circuit board) and passive (basically the psu manufacturer puts in a PFC choke) flavours.

In theory I agree with MikeC that active PFC should not cause more noise (and the corollary that passive, because it is a cheap & cheerful option, is likely to be inferior audibly as well). All I can say is my (1) active PFC psu was horrid: fortunately it expired (the switching transistors in the high voltage section to be specific).

My non-PFC I got from the Bracknell computer fair on Sunday - a no-name brand (PowerF or something daft, but has the same design/pcb as a Mercury/Kobian I got before) 350W. Cost £13 and (so far) is the best value I have had from psus. My dogmatism comes from spending over the odds on 'good' psus and being disappointed by them.

ZenmasteR · Post by **ZenmasteR** » Fri Jun 20, 2003 10:42 am

well I think I tried everything to track down the issue yet still not any closer,

I will be reverting to my older rig soon so I shall post back to report if I hear the buzzing again or not.

btw is it possible that dirty AC outlet voltage is making this happen or something nearby is messing with the frequency range etc?

dukla2000 · Post by **dukla2000** » Fri Jun 20, 2003 11:44 am

ZenmasteR wrote:btw is it possible that dirty AC outlet voltage is making this happen or something nearby is messing with the frequency range etc?

Highly unlikely that it is 'external' to your PC. The psu is spec'd for a reasonably wide voltage and frequency range so it would be pretty hard for Southern Electric to throw something your way that caused problems. So unless you have some really 'dirty' appliances on your spur I would doubt it.

Also, IIRC UK power is among the most reliable & closest to spec in the world. (They even do daft stuff like if the frequency drops below 50Hz, they boost it a little later to ensure that in a 24 hour period there are exactly the right amount of cycles!!)

ZenmasteR · Post by **ZenmasteR** » Fri Jun 20, 2003 12:56 pm

well I am the only tenant in a block of flats which are gonna be knocked down in couple of months,
mind you wiring the was replaced only 2 years ago!!!

BUZZING COILS whine whistling etc

BUZZING COILS whine whistling etc

Re: BUZZING COILS whine whistling etc