Power Supply works in one system, but not another

I recently built 2 systems, both using 500watt Antec Earthwatts supplies, and Asrock Extreme-4 motherboards.

The 1st came up and worked great.

On the 2nd, it was stone-cold dead. Nothing I could do to get a light or a fan to move. I tried an old Coolermaster
supply, and the system came right up. So I figured the power supply was dead, and sent it back to Newegg.
I decided to go with a Antec Basiq BP550Plus 550watt supply this time.


The new 550 watt arrived last night.

Well, I plugged it in, and had the same problem. Dead. No nothing. Put the old Coolermaster in there, still works fine.
Now I am suspicious.

I grabbed an old AMD computer my son uses. The Antec 550 Watt works fine in it.

The old Coolermaster has a 4-pin ATX 12V, and the AsRock has an 8-pin, so I just left 4 pins unplugged.
The Basiq has the newer 8-pin. Not sure that this is related, but it's the only difference I can come up with.

It's a pain-in-the butt to keep taking out and putting in a new supply. Any ideas on how to troubleshoot this?
Anyone heard of this before?

Thanks
8 answers Last reply
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  1. Hmm so the Asrock motherboard has an 8pin powr slot but the 8pin on the antec doesn't work but the 4pin on the coolermaster will. I would have guess the other way around. Is the 8pin on antec a solid 8pin or is it the 4+4pin so you could test it with just using 4?

    OooOoo you are using the 8pin designed for the motherboard and not using a PCIe 8pin? They look almost exactly alike.
  2. are you using the 8-PIN P2 or PCIE connector?
  3. crewton said:
    Hmm so the Asrock motherboard has an 8pin powr slot but the 8pin on the antec doesn't work but the 4pin on the coolermaster will. I would have guess the other way around. Is the 8pin on antec a solid 8pin or is it the 4+4pin so you could test it with just using 4?

    OooOoo you are using the 8pin designed for the motherboard and not using a PCIe 8pin? They look almost exactly alike.


    I am definitely using the 4+4 on the Antec/AsRock combo. I am going camping this weekend, so I will try your suggestion when I return.

    And I have an Antec + AsRock combo working great on the 1st computer I built. I may try swapping supplies, but I hate to take apart something that is working well.
  4. Emerald said:
    are you using the 8-PIN P2 or PCIE connector?


    No, I have the 2 6-pins plugged into the video card, and the extra "2" on one of the 6-pins hanging off the side.

    Good thought though.

    I would think one could not plug the Pci-E 6+2 into the 8-pin ATX, due to keying, but I have never tried it.
  5. Oh it works >.> well not so much works as fits.
  6. Update:

    Using:

    The old Coolermaster 550 with nothing in the 8-pin ATX connector on the motherboard: powers up
    Note I am just looking for power-on, not boot.


    The new Antec 550 with nothing in the 8-pin ATX connector on the motherboard: Nothing

    Using an old generic power-supply I pulled out of a case I inherited, and nothing
    in the 8-pin connector on the motherboard: Powers up

    It sure sounds like a received a 2nd bad supply, except that the Antec 550 works in another computer.
    And that means I received 2 bad Antec supplies in a row, which also seems unlikely.
  7. That is odd that it works in one computer and not the other. I've never heard of power supplies not working for certain motherboards.
  8. A brief update:

    I sent back the 2nd Antec, and installed an OCZ supply. It works just fine.
    This will just have to remain one of life's mysteries.
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