Loud (coil) noise from an MSI nforce2 board. Bad caps??

[jakah]

I got an MSI K7N2G board for free a while ago. The board seems to be totally stable, though it's generating a loud electrical noise. I can't tell exactly where the noise is coming from, but I think it's somewhere near the coil next to the mosfets, or from the coil itself. The noise is really loud, I can easily hear it from another room.
What do you think is causing the noise in this case, bad caps ? No caps on the board are visibly bad, no leakage or any other sign, but as I understand they can be bad anyway.

I have tried to identify the caps on the board, but I was unable to identify the brand of most of them. I have attached a few pics of the board, so you may be able to identify them, and tell me if they are bad.

What I could read from the caps:
3 x 1500uF 16V Rubycon MBZ
6 x 2200uF 6,3V KZG
2 x 1800uF 6,3V KZE
16 x 1000uF 6,3V KZG

Thanks
Jakob

[arneson]

Re: Loud (coil) noise from an MSI nforce2 board. Bad caps??

Others have addressed the toroidal buzz, as I call it.
Makes me wonder if multi layer PCB's could perhaps be vibrating between planes?

[Per Hansson]

Re: Loud (coil) noise from an MSI nforce2 board. Bad caps??

Your caps are excellent, United Chemicon and Rubycon...

You can identify the offending coil by touching it with your finger when the system is running (wearing a ground strap of course like you always should when working with ESD sensitive equipment)

While this thread might not tell you how to solve the issue completley it has some info that might help you to pinpoint it, like the use of the "hrping" utility for example

https://www.badcaps.net/forum/showthread.php?t=1710

[-HoNY-]

Re: Loud (coil) noise from an MSI nforce2 board. Bad caps??

What is a PCB revision?
What is i brand other caps (near memory, PCI, etc...). On mine is OST (bad brand).

I have two MS-6570 ver1.0 and both of them is unstable with Hi-end CPUs (Barton 3000+ & 2800+) with low-end CPUs run fine (duron 600 & 1600).

[jakah]

Re: Loud (coil) noise from an MSI nforce2 board. Bad caps??

Thanks for your replies guys!

Per Hansson: Your thread looks interesting, I will read it through.

-HoNY-: My board is ver:1 as yours. The only caps not mentioned in my first picture are the sixteen 1000uF caps (and a few small 470uF ones). I can't tell you the brand, but they are marked "1000uF 6,3V KZG" and their colors are green and white, as you can see in my first pic Don't your boards have the same caps as mine?
Are your boards noisy too ?

I have only tested the board with an athlon 1300 thunderbird (which ran stable). That one should stress the board pretty well I guess, as it consumes like 70 Watts.

[Per Hansson]

Re: Loud (coil) noise from an MSI nforce2 board. Bad caps??

Your KZE and KZG caps are United Chemicon caps, excellent brand (and models)

[Mustang]

Re: Loud (coil) noise from an MSI nforce2 board. Bad caps??

What is a PCB revision?
What is i brand other caps (near memory, PCI, etc...). On mine is OST (bad brand).

I have two MS-6570 ver1.0 and both of them is unstable with Hi-end CPUs (Barton 3000+ & 2800+) with low-end CPUs run fine (duron 600 & 1600).

My kid's pc has the same MB but a version 1.X (can't read the rev. there's too much crap in front). It has a very large passive NB cooler and heatsinks on the mosfets. It wouldn't run stable much past 180fsb so I put an 80mm fan over the NB and mosfets and I got a stable 192fsb x 11 multiplier on his 2500XP-M. It's only a 2 phase VRM and I think the caps (although good brand) are light on capacity. Heatsink the mosfets and go with a slightly higher rated cap. It should run a lot more stable