x5000 CPU Fan connector cause crackles
  • Butterfly
    Posts: 74 from 2005/10/31
    As questions I have independent of the OS used on X5000, maybe there will be some help about:

    Lately was tired up on the absolutely noisy sound of the default CPU fan coming with x5000, and about to replace it. And no surprise it was so noisy, the default one is DELTA AFB0612EHD-A 12V 3.72W Cooling Fan, which has 6600 RPM and Noise 45 dBA!

    So got Noctua NF-A6x25-flx. This is a 60x60 cooler size, give 3000 RPM at maximum and just 19.3 dBA. And fits well instead of an old one.

    It's moving a bit slower than the default one (actually in 2 times, 6600 RPM vs 3000 RPM), and so cause a little bit more hot heatsink (not _THAT_ hot, but a little bit more) and can be connected and to CPU Fan connector on motherboard (so can control speed), and to PSU so to have the same more or less fast speed. But it very silent.

    Now, what I found on my motherboard, is that does not matter which cooler I use (the old one, new one) if I connect it to the FAN CPU connector on the motherboard, I have heard little crackles. Which at first may sound like issues with the cooler, but no, when I connect the same cooler from PSU, there are no such crackles.

    Do any of you, if listen very carefully, when connected to the CPU Fan, heard any little crackles (i got that with both Fans. just with noise one I was thinking always its Fan crackles itself, but now Noctua too). But then, if I connect Noctua to the PSU power, I heard _no_ crackles. Meaning those little (very little) crackles coming when I connect the cooler to the CPU fan power connector on the motherboard. Maybe those are electrical leaks ?:) Or maybe that how MB trying to "chill" the cooler? Dunno, but sounds strange. I at first think that something can be under the heatsink maybe or so, but when I connect it to PSU power, then no little crackle sounds can be heard.

    I made a little video so you can hear what I mean (power on volume more) so you can compare if you have that too or not:

    1. Noctua connected to the CPU fan on a motherboard: https://youtu.be/ncsCGYOxNSw

    Check there especially on the from 10 to 20 seconds (and turn the volume very up), you will hear what I mean. Sound like something with Cooler, but is not (both coolers produce the same crackles, an old one, and a new one). More of it, if I connect a new one to the PSU power (and the rotation looks the same by speed), I have no crackles! See:

    2. Noctua connected to the PSU power: https://youtu.be/M9gq9pZvAs4
    Check there from 20 to 30 seconds, no crackles.

    So it did sounds or like electrical issues (which if I remember I had from the very beginning), or some "CPU control slowing down the speed" or something. Did anyone have that or have a clue? Thanks!

    [ Edited by kas1e 24.12.2020 - 05:33 ]
  • »24.12.20 - 05:11
  • Priest of the Order of the Butterfly
    Priest of the Order of the Butterfly
    Posts: 769 from 2003/3/4
    From: #AmigaZeux, Gu...
    Maybe the board is sending a PWM signal to a fan that expects an attenuated voltage or vice versa.

    For me, three pins means PWM, but this was never a standard.
  • »27.12.20 - 14:51