Connect with us

Help with 6 pin Server Fan / mod to 4 pin

Discussion in 'General Electronics Discussion' started by ins0mniac, Jul 13, 2014.

Scroll to continue with content
  1. ins0mniac

    ins0mniac

    3
    0
    Jul 13, 2014
    Hi All,

    I'm new to all this so bear with me, I've picked up a HP DL120 G6 rackmount server.

    The fans on this server are expectedly very noisy and I can't find any quieter 6 pin fans to directly replace them with.

    So, this brings me to my task of either modding a 3/4 pin fan getting it to work or using a fan controller to lower the voltage and drive the existing fans. (though I'd prefer replacing them)

    The dual fans (12v 1.86A) and pin out looks like:
    I've already tried connecting a 3pin fan to the board (12V to Pin3, Tach to Pin1 and Ground to Pin2). The result of this was the Fan spins at start up but the server complains about a failed/missing fan and refuses to continue.

    My research tells me the culprit could be Pin 5/Alarm needs to be driven to 0v to tell it everything is ok. Can someone advise how this should be best done?

    I tried a wire from pin 5/Alarm on the board to the computers chassis in hope this would do it, but it didn't work, was abit of a flimsy connection though.

    If anyone has done anything similar or can advise of a solution / technique to get 3 or 4 pin fan connected it would be highly appreciated!

    Thanks
     
  2. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,374
    2,769
    Jan 21, 2010
    Unless the fans are failing and are noisier than normal, expect them to be noisy and don't expect to make them quieter.

    They're noisy because they are small diameter, high RPM, high airflow fans. The case almost certainly dictates the diameter, and the required airflow will dictate the RPM. I suspect the unit consists of 2 fans for redundancy, and if so, that will only make them noisier.

    It's also not unexpected that if the server detects one fan not working it will run the remainder at full speed. Do you have a failed fan?
     
  3. ins0mniac

    ins0mniac

    3
    0
    Jul 13, 2014
    Hi Steve,

    I guess I should of mentioned, I'm removing the motherboard from its rack mount case and putting it in a bigger standard case which will have better airflow, It has 3 CPU fans and 1 system fan (4 in total), none are redundant and none have failed.

    I appreciated these are designed to be noisy, but I will be monitoring the CPU temps to ensure its within levels and in case of failure.

    Are you able to advise on how to best ground a pin to 0v or swap these out...regardless of risk involved.

    Thanks
     
  4. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,374
    2,769
    Jan 21, 2010
    I would try pulling pin 5 low. Do it via a 100 ohm resistor just to be careful, although I think you could just ground it.

    With a larger case and more airflow, the rack mount style jet engines are probably no longer required :)
     
    ins0mniac likes this.
  5. ins0mniac

    ins0mniac

    3
    0
    Jul 13, 2014
    Cheers - will let you know how it goes.
     
  6. fatfrog50

    fatfrog50

    1
    0
    Apr 16, 2020
    hi, I'm trying to do the same thing. but with dual water cooling on the boards CPU, and whit some less noised fans. I have tried also to ground 0v pin 5, it spins up and stops. as described above, my system is whit 8 fans redundant, and it measures if some fans are bad, it only measures fan connection 1-6, not actually fans, so I think maybe when the current is dropping it makes a false, and shut the system down. so maybe if I make a " fake " usage of voltage, fx a diode I can trick it to boot normally, ore will I burn my house down, I don't know, I'm not an engineer, I just make trash great again .. regards.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-