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Burnt 20-pin molex connector

Discussion in 'Hardware' started by abreev8, 15 May 2006.

  1. abreev8

    abreev8 New Member

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    A picture's worth a thousand words, they say:

    [​IMG]

    So the 3.3v pins on my motherboard power connector aren't looking too good. They've been like this for a while now and I'm sure continuing to use it hasn't helped, but instead, just made the problem worse. As far as I know of, there are two possible causes for something like this. Either too much demand for the 3.3v rail or the connector was seated poorly. Since I have a decent power supply and not too demanding hardware, my guess is that it was the latter. The good old volt-o-meter tells me that the PSU is putting out a solid 3.30v. ASUS probe reports much lower voltages than that on the motherboard. They've gotten as low as 2.8 which was low enough to cause stability problems. After trying to clean it our for a while with isoprpyl alcohol and making sure the connector was seated nicely, it reports around 3.10-3.15v.

    Question 1:
    Is there a way I can check the voltage that my motherboard is getting with a voltmeter? Or is ASUS probe reliable enough? I have an ASUS P4P800 deluxe.

    Question 2:
    Any good ideas on how to try and fix the problem? I could replace the pins in the power connector, but there's no way I can replace the pins on the mobo side. Cleaning seemed to have some effect, though it's nearly impossible to clean them, and unless I can find a better solution, the problem only gets worse with time.
     
  2. ElThomsono

    ElThomsono Well-Known Member

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    To check the voltage while it's on the motherboard, you could always put the voltmeter onto the other side of the pins, sticking out the bottom of the motherboard.

    By continuing to use it in that state you're risking your hardware, I'd stop using it 'til you get it sorted. Is replacing the whole thing an option?
     
  3. abreev8

    abreev8 New Member

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    By whole thing do you mean the connector and pins? Yes, that is a possibility. Certainly not expensive. ;) But again, there's nothing I can do about the motherboard side of the connection.
     
  4. Guest-16

    Guest-16 Guest

    Seen that before with a 450W powering a dual socket A machine. The 5v lit on fire.

    It's drawing too much current and making the wire too hot. If you can upgrade to a 24pin (if the mobo can take it) I'd definately recommend it for greater distribution (if the 4 extra pins cover that voltage, that is).
     
  5. felix the cat

    felix the cat Spaceman Spiff

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    who makes the powersupply and how old is it?
     
  6. Krikkit

    Krikkit All glory to the hypnotoad! Super Moderator

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    That's a testament to PSU makers really - the circuitry can cope with high enough current draw that the wires burn before it breaks.
     
  7. abreev8

    abreev8 New Member

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    It's a 350w Antec that's 2-3 years old. It seems just fine to me. The connector, of course isn't.

    What draws on the 3.3v rail anyways? The agp slot? I only have an old 9600 pro.
     
  8. hitman012

    hitman012 Active Member

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    The draw on 3.3V is almost exclusively RAM and PCI signalling, although older boards also used it for AGP power as well. What voltage are you running through your RAM and how much of it do you have?

    If you can upgrade to a 24-pin power supply (assuming that your board is compatible), then it'd probably help to rectify the problem by sharing the current more evenly.
     
  9. RotoSequence

    RotoSequence Lazy Lurker

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    You could also try replacing the wire with a thicker, lower resistance one.
     
  10. abreev8

    abreev8 New Member

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    The motherboard is 20-pin. All that I've got in the PC is 1 gig ram, a 9600 pro, and a wifi card. There's certainly plenty of power to supply my needs. The problem is that at some point, the connector was seated poorly and caused the pins to oxidize, thus permanently reducing the effectiveness of the pins.

    Unless anybody else has any othe suggestions, I guess the best course of action would be to just replace the pins and see if that helps.

    EDIT: And I haven't increased the voltage on anything. I've done some expirimenting with overclocking my vid card, but that was before this happened.
     
  11. TMM

    TMM Modder

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    Most likely a dodgy connection or a short on the mobo.

    The wires on most PSUs are rated to take around 20Amps. And 20x3.3 = 66W. I highly doubt your using 66W of 3.3v --- for 5v and 12v, maybe, but definately not 3.3v (the only real power users for 3.3v are ram and your graphics card, and pci cards.) It could however, be a fault with your motherboard shorting the 3.3v with ground somewhere.
     

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