P5NSLI - doesn't boot or start unless it's warm (?)

Discussion in 'Asus' started by Asus Guy, Apr 3, 2007.

  1. Asus Guy

    Asus Guy Guest

    I've been working with a new system built around a P5NSLI that I
    bought about a month ago. It's Rev-2, and I've updated the bios to
    I've got 6400 core-2 duo, 2 gb ram, and am using the bios defaults (no

    What I've noticed is that the board will not POST from a cold start.
    When I first turn it on cold, it will not post at all. If I hit reset
    or power-cycle it, eventually after maybe a minute or two it will get
    through the POST without locking up, but it will usually hang during
    XP startup. After another minute or two it will get through XP
    startup and when it gets that far the system works fine.

    If it's been running for 10 or 20 minutes and I power it down it will
    start right back up no problem.

    So it seems that it wants to be warm before it's able to fully start.
    Anyone heard of that before? Any ideas?
    Asus Guy, Apr 3, 2007
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  2. Asus Guy

    Say Cheese Guest

    This board picks bad bios defaults for the memory timings. Slower is not
    better if it is too slow for the memory. Also the board only likes certain
    (published) memory brands. I would fiddle with the memory timings in the
    Say Cheese, Apr 3, 2007
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  3. Asus Guy

    Asus Guy Guest

    Even when it's using SPD timing?
    Well, I'm using Kingston KHX6400D2LLK2/2G.

    There are 4 memory slots on this board - 2 yellow and 2 black. Is
    there any difference between the yellow and black? (I know the 2
    stick I have should go into either the yellow or the black, but is one
    better than the other?)
    Asus Guy, Apr 4, 2007
  4. Asus Guy

    Say Cheese Guest

    My P5NSLI bios defaults did not pick up and use the SPD timings (found using
    reporting software). My two 512 mb memory sticks are in the black sockets -
    I believe that's what the manual said do...I found directions somewhere.
    Say Cheese, Apr 4, 2007
  5. Asus Guy

    Paul Murphy Guest

    Sounds almost certainly like a Power Supply Unit issue to me. I have a setup
    that does the opposite ie wont post or reboot when it's warm/been running a
    while but let it cool and it works fine. A different brand of PSU doesn't
    exhibit this issue with the rest of the hardware unchanged. Have you a spare
    PSU you can test it with (perhaps borrowed out of another PC)?

    Paul Murphy, Apr 7, 2007
  6. Asus Guy

    Asus Guy Guest

    First, here is an update.

    We're talking about P5NSLI, Rev 2, flashed with 1001 bios. From a
    cold start, when powered up, it will just sit there, no keyboard LED
    flash, no beep, no post, no video. If I leave it in that state for
    about 3 or 4 minutes and then hit reset, the system starts just fine -
    it beeps, I get the post, it starts XP and is rock solid. If I do a
    warm power-down, I can start it back up no problem.

    I have replicated this with another system with a different P5NSLI,
    different CPU, different power supply, different video card, and a
    different bios (original 601).

    What the two systems have in common is RAM type:

    Kingston KHX6400D2LL/2G or KHX6400D2LLK2/2G (I don't recall which one
    at the moment).

    And I know that it's not the RAM that needs to be warm for the system
    to post. I've substituted cold ram into a warmed system and it boots
    Asus Guy, Apr 9, 2007
  7. Asus Guy

    Ken Guest

    The problem must be the Power Supply Unit.
    Ken, Apr 9, 2007
  8. Asus Guy

    Paul Murphy Guest

    And even though the OP has tried another one, I think it's likely that the
    spare was also not up to spec or faulty. The symptoms point to the PSU -
    perhaps the OP can post details of the PSU used in both cases or try a more
    powerful one.

    Paul Murphy, Apr 9, 2007
  9. Asus Guy

    Asus Guy Guest

    On the first system, the PSU is this:


    According to the box, it's 600 Watt.

    On the second, it's a Zalman 400 watt unit (don't recall the model

    On the first unit, on a hunch that the problem is the PS, I unplugged
    the CD drive, the hard drive, the floppy drive, and I pulled 1 stick
    of ram out in order to bring the load down. But the cold-start
    problem was still there.

    I highly doubt that I'm seeing the same problem on two different sets
    of hardware and the problem in both cases is the power supply.

    I think it's the memory, which is this:

    Kingston KHX6400D2LLK2/2G


    They both are using that type of memory.
    Asus Guy, Apr 9, 2007
  10. Asus Guy

    Asus Guy Guest

    In the Asus forum pertaining to the P5NSLI, there is a reference to
    someone receiving (back in January) a Rev-3 replacement board as a
    remedy to an unspecified startup problem.

    I took delivery of several Rev-2 boards in early March. It would piss
    me off if they were up to rev 3 at the time.

    Anyone else buy this board recently? If so, what rev was it?
    Asus Guy, Apr 10, 2007
  11. Asus Guy

    Paul Murphy Guest

    But you said you put cold ram in a warm system and it still worked OK, aside
    from this I've never heard of RAM temperature sensitivity causing failure to
    post. If you don't want to risk being lumbered with a PSU just in case this
    isn't the problem (and I'm still sure it is as temperature related booting
    problems are a classic sign), take your base unit into the shop selling the
    PSU and get them to test it for you. I've heard of SLI boards needing 850
    Watt PSUs so 600 Watt may be stretching it (and 400 Watts wont be enough).
    Some boards can be very picky about PSUs, so it may be worth finding what
    sort Asus recommends for this board.

    Paul Murphy, Apr 10, 2007
  12. Asus Guy

    Asus Guy Guest

    Yes, which means that for the system to post, it must be some
    component on the motherboard that must be warm, but not the ram (the
    ram can be cold or warm).
    No - I've shown that the ram temperature doesn't matter. The system
    will post and start fine only when the motherboard has been pre-warmed
    for a few minutes.

    If cold ram is put into a warm motherboard, the system starts fine.

    If the ram is warmed with the board, then again the system starts

    If the motherboard is cold, then it won't start - period.
    On TWO sets of hardware - with completely different PSU's ?! You
    still think it's PSU related ?!
    I'm not running these systems with dual video cards. One system has
    an NVidia 6600 with a heatsink (no fan), the other has Nvidia 7900GT.

    So you're saying that the motherboard, 1 stick of ram, and a video
    card (and a keyboard and mouse) is going to need 850 watts? No way.
    I doubt it's going to need more than 200 watts in that configuration.
    Asus Guy, Apr 10, 2007
  13. Asus Guy

    Paul Murphy Guest

    Yes! - Try it the safe way (using the selling shop to test it).
    I saw your post about testing the system in a minimal configuration and
    you're right that in that case an 850 Watt PSU wouldn't be needed but for
    this board fully loaded with power hungry video cards and bits (presumably
    you eventually intend to get a second video card at some stage) it will be
    needed. It's always better to get a PSU rated beyond what the setup will
    actually use - the machine wont use all 850 Watts if you put in that PSU,
    just what it needs but with a dual core AMD setup and Nvidia VGA (even with
    a heat sink and no fan) it will need more than 200 Watts. Check to find if
    there is a preferred PSU with Asus.

    Paul Murphy, Apr 10, 2007
  14. Asus Guy

    Asus Guy Guest

    We buy parts from a distributor that's 100 miles from us, so there's
    no shop involved.

    I'm going to call them today and ask if there's a rev-3 version of
    this board.
    Yes, and even in that minimal configuration the board still doesn't
    post when cold - and you're still saying that it's PSU related in that
    situation as well?
    No. This dual video card stuff is bullshit. The systems I'm building
    with these boards will probably never see a video game running on
    I know there is a list of preferred (approved) ram for this board, but
    I've never seen a motherboard made by anyone with a list of preferred
    (or approved) PSU units.
    Asus Guy, Apr 10, 2007
  15. Asus Guy

    Paul Murphy Guest

    Ahh... that makes it tricky. I suppose you could ask them if you could
    return it if it turns out to be unsuitable but even if they permit this (in
    the UK a 7 working day cooling off period is provided under the distance
    selling laws), you'd still need to pay the postage costs if you returned it.
    See what they have to say about this problem at the same time.
    When my PC (its actually a Tyan dual CPU server machine) exhibits its
    failure to reboot or boot when warm problem unplugging the DVD, Zip drive
    and other various bits loading the PSU doesn't make any difference, yet a
    different brand of PSU (of the same power rating) doesn't exhibit the
    problem under any circumstances.
    You're preaching to the converted! Back in the days when you could get 3Dfx
    add-in 3D Accellerator cards they also offered a similar feature (which
    worked in a different way). Although we see it as marketing hype, many go
    for it, presumably for boast value if no other reason. Although I've not
    worked on such a machine, SLI machines can use alot of power (especially
    with those dual core CPUs).
    Tyan do but then they predominantly provide server boards. Perhaps your
    distributor can suggest a suitable 'tried and tested' in this configuration

    Paul Murphy, Apr 10, 2007
  16. Hey I came across this post, I buy these boards ALOT! And have the
    same problem, I send it back to asus to get it fixed and they sent it
    back the same way, I have swapped out every component and the only
    thing I can come across thats the same is the board, anyone come
    across a solution to this yet??
    Computerguy101, Apr 21, 2007
  17. Asus Guy

    Asus Guy Guest

    You might want to read this thread:


    (or try this: http://tinyurl.com/yqoydb)

    I bought 6 of these boards about 7 weeks ago, and at first 4 of them
    had the cold start problem, but one of those has spontaneously fixed

    I called Asus a week ago (April 12 or 13) and opened a trouble report
    with them regarding this cold-start problem.

    I asked if they had received any other reports about this, and they
    said no. They wanted me to check if it was a grounding problem by
    powering up the board without it being mounted in a computer case,
    which I've done with 5 of the 6 boards I have, and it made no

    If you are telling the truth - that you have told Asus about this
    problem and are getting replacement boards from them, then they are
    lying, and anyone else reading this and about to contact Asus for a
    replacement should mention this to them (that they DO know about it,
    and you're not the first to report it).

    The best theory so far is that this problem is only happening on
    *some* P5NSLI boards, and only when the CPU is a Core-2. I've seen it
    happen with E6300 and E6400. Maybe it doesn't happen with E4300 (just
    speculating - it's an older version of the Core-2 isin't it?).

    What nobody has done yet (that I know) is to take a board with the
    problem and try a Pentium on it and see if the problem is still
    there. I don't have any socket-775 pentiums, but I do have a Celeron
    D that I might try.

    I've noticed that the flash bios chips always seem to have a mark on
    them, written in a dark magic marker. I think I'm seeing a pattern
    where there is an X mark on the boards with the cold start problem,
    and a check mark on the boards that are ok. Have a look at the boards
    you have with the problem, and the boards you're getting back as
    replacements and tell me if you see this mark.

    If you've been buying this board for a while, do you know when this
    Rev 2 came out? All my boards were Rev 2.00G.

    The P5NSLI has been around for almost a year now. When did you start
    seeing this problem with them?
    Asus Guy, Apr 22, 2007
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