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3 pin or 4 pin power connector- HELP!

By algoespanol ยท 13 replies
Oct 11, 2007
  1. My CPU's fan has a 4 pin power connector, however, my motherboard has no 4 pin power connector, it only has a 3 pin, any suggestions as to what i can do? Can i still use this 4 pin with the 3 pin or do i need to get a new fan/mother board?
  2. matav

    matav TS Enthusiast Posts: 144

    The fan has a four pin power connector which must be looking like the power connector used to plug IDE HDD's or DVD/CD ROM's.
    so just use one of those (which comes out from the SMPS)
  3. algoespanol

    algoespanol TS Rookie Topic Starter

    It looks like the small 3 pin power connector that would plug into the board. But, instead of having 3 wires, it has 4. It has the black, red, yellow, and then a blue. If i'm not mistaken, just having the black, red, and yellow plugged in will make the fan work right? Because the thing fits perfectly over one of the small 3-socket power supplies on the board and the black, red, and yellow plug in.
  4. Rik

    Rik Banned Posts: 3,814

    You have a 4 wire fan then. Red = 12 volts , black = ground, yellow = speed sensor, blue = speed control (if memory serves).

    You could rewire it so it matches the 3 pins on your mobo or replace it with a 3 wire fan as they arent very expensive.
  5. Spleenharvester

    Spleenharvester TS Enthusiast Posts: 47

  6. radiorara

    radiorara TS Rookie

    Hi NOOB here in need of help

    I am building a new system. MSI K8T Neo2 V1 Socket 939 with a AMD Opteron Model 175 with stock amd retail fan. Its has a four pin connector. Black/Red/Blue/Yellow in that order in how it would connect properly to the motherboard. The motherboard has a three pin connector for cpu. If my memory serves me in the past when I built a system I used a special cable that converted a 4 pin cpu fan to a 3 pin mobo connection and used the power from a 4 pin molex running off the psu so as not to damage the motherboard from higher power psu coolers. I thought I was purchasing 2 these and what came in was a three pin male to three pin female with molex 4 pin. The female end has only the yellow wire attached while the male end has yellow/black and red attached. My questions are would this thing work? Im not sure because the the orientation of the cpu cooler wires black/red/blue. Can i hook up the cpu fan directly to the mobo? (I dont want to damage the mobo in the process.) Do i need that special 4 pin male to 3 pin female to 4 pin molex connector? Some ppl have told me u can hook it up directly as the yellow wire is not needed. The only way to connect it properly would mean that the black/yellow/blue wires are connected and the yellow would not be connected at all. Any suggestions/comments?
  7. Rik

    Rik Banned Posts: 3,814

    Match the colours up but dont use the blue, it's as easy as that.
  8. radiorara

    radiorara TS Rookie

    Re: Noob Questions

    Due to the orientation of the blue wire I cannot just match it up. The blue is the third wire in and the yellow is the fourth. The connector only goes into the mobo one way. With it properly attached the black red blue would be connected. I suppose i could connect it with just the black/red and cut the blue wire. I suppose I should just cut the connector and rewire it to match the orientation of the mobo header correct? I was just looking for a easy safe alternative without replacing the stock amd cooler.
  9. Rik

    Rik Banned Posts: 3,814

    It is possible to swap the wires around. If you press on the small opening with a knife or small screwdriver you can remove and refit the wires.
  10. radiorara

    radiorara TS Rookie

    Thank you my friend. I did as you so expertly stated and pictured and was able to reorient the wires and even use the 3 pin to 4 pin molex adapter with rpm monitoring. It went together well excpet when I poer up my MSI K8T Neo2 mobo with Dbracket 2...all lights illuminate which says processor may be damaged or installed incorrectly. I know i put it in properly and rechecked it. Could it be that the bios isnt updated and its not recognizing the processor? I know this proc is compatible with this board but it might be in a future bios revision.
  11. Rik

    Rik Banned Posts: 3,814

    Try clearing your cmos, your mobo manual will tell you how to do it.

    Let me know if that doesn't help and i will make more suggestions.
  12. radiorara

    radiorara TS Rookie

    Amd K8t Neo2

    Yes Sir I did that twice to no avail even before u stated that to me. I went to MSI's website and downloaded all the drivers and utilities and latest bios. I bought this motherboard used and its the Ver1. I wish i had read the auction more carefully and bought the ver2 but oh well. It does state this processor is compatible Opteron 175 200 fsb ratio 11. It looks as if as of version 9.1 bios that amd e stepping and dual core cpu's are supported. I without another cpu have no way to tell as I cannot get this thing to post. Any help would be greatly appreciated.
  13. radiorara

    radiorara TS Rookie

    Im gathering that I should just buy another cpu and update the bios, then try reinstalling the opteron. Is that correct? Or are there any other alternatives?
  14. Rik

    Rik Banned Posts: 3,814

    Another cpu seems to be the only way to test really.
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