Video card wont work in top PCI Express slot on sli board

By shakezoola ยท 11 replies
Jan 6, 2006
  1. Hello,
    I just got a Asus A8N-SLI mother board and a pny 7800gt video card. The card only works in the bottom pci express slot though, when i try to plug into the top the monitor light keeps blinking like nothings going through. Everything seems to work fine when in the bottom slot but i am worried about the heat. I have my sound card close to that so theres not much flow between like their would be in the top slot. (also the top slot is blue, bottom is black, if that makes a difference) I left the default set at single card mode on the motherboard. Also being in that slot is the card running at full capacity? 16x?
    My other specs are:
    1gb Corsair value select ram
    Antec 450Watt SmartPower 2.0 PSU
    AMD 64 3700

  2. Jaquio

    Jaquio TS Rookie Posts: 26

    mmm... Check out the BIOS option for the SLI cause it could be that just one slot is enabled (the bottom on)...
    about the heat issue... can you move the sound card to another slot?...
  3. vnf4ultra

    vnf4ultra TechSpot Paladin Posts: 1,360

    I'm not 100% sure, but I think if you have one card, you are supposed to run it in the bottom slot, and the top slot is only for the second card. Could you move your sound card down one pci slot?
  4. Jaquio

    Jaquio TS Rookie Posts: 26

    nice one... ive never heard of that... but it could be... who knows... let me get info about SLI configs..

    PUTALE TS Rookie Posts: 126

    it sounds to me that your top slot maybe not working. Maybe you should consider RMA the card. Did you try to clear the cmos and then put the card on the top and see if that will work.

    I am not sure which asus sli mobo you have, the newer sli x16 mobo will run at 16x on both slots, while the older mobo will only run 8x for the second slot in the sli mode.

    BTW, when you said bottom slot, do you mean that the blue color one? I think the blue color is actually the primary pci-e slot for single card. Check your manual to see if you have a single card, which slot should you use.
  6. vnf4ultra

    vnf4ultra TechSpot Paladin Posts: 1,360

    I'm pretty sure I saw a board that used a single card on the bottom slot, but for the a8n sli, it seems you should be putting it in the blue slot, which is at the top, if it doesn't work, I'd guess the board is defective, if you can get the video card to work in the other slot(or in another pc).
  7. shakezoola

    shakezoola TS Rookie Topic Starter

    I havent tried clearing the cmos, i'll give that a try. I really hope its not a bad board, but so far thats the feeling i'm getting. When i get home i'll take a closer look at the manual and see if it says anything about using a single card and which slot it should go in. thanks for the help
  8. JohnK93

    JohnK93 TS Rookie Posts: 44

    Should be in the blue slot

    I also have an A8N-SLI (delxuxe) and in this mobo the card should be in the blue slot, which is on top. If I try to use the bottom slot only, a red warning LED comes on on the mobo indicating the card is in the wrong slot. Unfortunately, sounds to me like a problem with the mobo, but could also be something in the SLI setup in the BIOS.

  9. Jaquio

    Jaquio TS Rookie Posts: 26

    Just as i wrote... but make sure to check everything before going to buy a new Board...
  10. Row1

    Row1 TS Guru Posts: 325   +13


    i have the asus a8n-sli
    my info is the same as others- for single card, just the top slot works.

    when i built mine, the vid card would not work. i took a regular pci vid card from another comp, put it in a regular pci slot, and got video. i guessed that my vid card was bad. i rma'd the pci-ex vid card and got another. that pci-ex card worked with no problems right away in top pci-ex slot.

    so if i were you i would either try another pci-ex card (if available) in the top slot or rma the mb.
  11. shakezoola

    shakezoola TS Rookie Topic Starter

    after downloading a couple manuals from the asus tech site one said i had to use the blue slot, the other said i could use either slot for single card use. They were both for my mb, but different version, dont know which one i have in print since i'm at work right now.
  12. PUTALE

    PUTALE TS Rookie Posts: 126

    i think you can use either slot for single card provided that you enable SLI (whichi will render both slot running at 8x pcie speed). If you want full 16x lane, then you would hae to use the slot that's supplying the 16x speed and disable the SLI under bios(I believe that it is the blue slot that's the one to go for the 16x).
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