New system wont boot... fans spin half way and stop

By bobmoin · 11 replies
Jan 10, 2006
  1. Hi,

    I am having trouble getting my new system to boot and am so frustrated. I dont know what to do.

    CPU= AMD 3700+ (ada3700bnbox)
    mobo= Asrock 939s56-m

    When switched on the fans all spin once and then stop. There are no bleeps.

    It is not the PSU. It cannot be... I have tried several. It is not the ram. I have tried many sticks.

    The only thing I can think is that the mobo does not support this processor without a bios upgrade- thats what Asrock's website tells me. But I caanot upgrade the bios without the system booting up.

    Could this cause the system to act as it is doing? Or is there some other possible explanation?

    Thanks for any help
  2. snboarder113

    snboarder113 TS Rookie Posts: 18

    do you have case fans? do they continue to spin ? or just spin once, if only once it has to be a power issue
  3. bobmoin

    bobmoin TS Rookie Topic Starter

    Thanks for replying

    All three fans (heatsink, Graphics card, and case) only spin once for a fraction of a second.

    I thought it was a PSU problem so I bought a brand new 450W antec ATX 2.0 psu and I get exactly the same problem. Seems like I wasted another £40 on that.
  4. kirock

    kirock TS Rookie Posts: 1,221

    All I can suggests is typical problems with a new build:
    1) Ensure the mobo stand-offs are installed correctly (including the insulation washers) and the mobo is not touching any part of the case.
    2) The CPU heatsink/fan assembly is properly installed and in perfect contact with the top of the CPU and you have used thermal paste bewteen the heatsink and CPU.
    3) Make sure the 20/24pin PSU connector is plugged into the mobo correctly and securely.
  5. iss

    iss TechSpot Chancellor Posts: 1,994

    if the above is true then the only way your going to get into the bios is to install a CPU that the board does support.
  6. nork

    nork TS Maniac Posts: 306

    Do you have your mobo on the bench or installed in a case?
    If its not turning on, you should have it out of the case to make sure its not a problem with a standoff as a standoff problem can emulate a power supply problem and you dont know which problem it is thats causing your pc not to boot up.

    You said you bought a new "450W antec ATX 2.0 psu " Normally that would be a great ps but just check and make sure its the newest atx standard as im not sure of the newest standard but i do believe its above 2.0. It might be 2.03 or higher, will have to look it up.
  7. bobmoin

    bobmoin TS Rookie Topic Starter

    thanks so much.

    I was convinced this was not the issue, but did what you said and have it all sorted now.
    Thanks again. : )
  8. nork

    nork TS Maniac Posts: 306

    Hey, thanks for letting me know! So often what seems not the case is actually the case, lol.
    I've been building pcs for about 6 yrs now so i have seen a lot, like dead mice fried to mobos, etc, etc, lol.

    On the other hand, yes, i did suggest you take the mobo out of the case, and i did mention the standoffs, and maybe the first to put the 2 together, but kirock WAS actually FIRST in mentioning the standoffs, so he should get credit for this one.

    I once had a guy bring a pc in, said it wouldnt start, set it on the table. On the way out the door i told him "I bet you just drywalled your basement!"
    He said "How could you possibly know that?" I said, "well, regular dirt, cobwebs, and plain dust are all grey in color, but look at your power supply fan, its so white it stands out like a sore thumb." Sure enough, i opened the case to find the cpu\heatsink\fan so totally full of drywall dust that the P3 900 cpu had shut the pc down to save itself before it burnt to a crisp! This guy never doubts my word now, lol.
  9. kirock

    kirock TS Rookie Posts: 1,221

    I do believe that's what I suggested. :stickout:

    Good stuff glad to hear you got it sorted out.


    Edit: Thanks Nork for the credit I didn't see that line, I was just having some fun with this post anyways and now I feel like a real heel. :blush:
  10. nork

    nork TS Maniac Posts: 306

    Lol, this is really funny.
    I am on another forum that doesnt even have an edit, how would you like that, lol! Caught me a few times, lol.

    No problem. I understand because a lot of people will take credit when someone else actually started the ball rolling but their poor little ego wouldnt allow them to credit the other guy.
    If i ever do that its only in error, i try and be fair, thats how i even caught that you were the first to mention the fix. Before answering the last post i checked to see if anyone else mentioned the standoffs as i thought someone did.
    I always say mistakes are easy to make but hard to admit, lol.
    So, no need to feel bad about your comment.
  11. nork

    nork TS Maniac Posts: 306

    I was just re-reading this and its a very good point that kirock and i mentioned, the standoffs.
    Very often a standoff issue can emulate a power supply issue.
    The reason for my statement:
    There are solid metal rings around certain holes. This is where a metal screw can be placed.
    There are no solid metal rings around certain holes. Best not to place a screw there as it will interfere with traces in the mobo and it wont start up!
    Here you should use a plastic standoff or even no standoff, as the case may be.
    Not only that, but there are certain screws that shouldnt go in mobo holes as they overlap onto the traces, causing a ground that will prevent pc from starting up. Use screws that dont go over the metal ring!
    Thats one of the reasons its best to build your new (used but new to you) pc on the desk instead of building it inside the case!

    I have a tutorial for troubleshooting, wonder if the mods here would want to see it and maybe sticky it.
  12. Cartz

    Cartz TS Rookie Posts: 82


    I knew from the thread title that he was getting a short somewhere in the system. Came in here to help and low and behold you guys have got him sorted out already.

    Good show
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