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New PC will boot and shut off after a few seconds

By genesis211 ยท 8 replies
Nov 25, 2006
  1. Just built up a new system, Pentium D processor, 512 memory, 200gb hard drive . . .
    I am able to power up the system and get to a prompt to Insert a boot disk (as I haven't yet loaded anything on the hard drive) then the system will power itself off after a few seconds.

    The CPU fan is running properly.

    I am using a 380W P/S and am thinking that it may not be sufficient.
    Any ideas? Thank you
  2. Grafficks

    Grafficks TS Rookie Posts: 302

    It sounds an awful lot like a heat problem.. Can you power up long enough to get into the BIOS and check the CPU temperature? Are you sure the CPU HSF if fastened correctly? Maybe you should take it off and put it on again. Are you using stock thermal pad or aftermarket silver thermal paste?

    What brand is your PSU?
    Use this and calculate how much power you should need for all your hardware.

    Good luck :)
  3. genesis211

    genesis211 TS Rookie Topic Starter


    Thank you for the insight. I am using the stock thermal pad. Would it be better to use something else? I did have a bit of trouble getting the CPU fan to seat properly to the motherboard...any trick to those white clips? I can get two to click in properly--the other two don't seem to seat as well. Is there another way to hold those in place.
    Thank you
  4. Grafficks

    Grafficks TS Rookie Posts: 302

    It's ok to use the stock thermal pad, but it's always better to get something like Arctic Silver 5, but it's not required.

    The stock fan and mounting system for Intel's LGA775 socket is pretty tricky! This is confusing, because Intel's socket 478 fans were perfect in every way! I had trouble myself mounting the LGA775 fan the first time. Turns out I didn't mount it properly and the CPU temp showed 90*C in the BIOS, at which point I powered off immediately.

    All 4 pins must be fastened correctly, and the heatsink must be applying full pressure onto the CPU at all times for it to cool effectively. The manual told me to listen for a "click" of the pin to confirm that it's installed correctly, but I heard about a hundred different "clicks" while installing it, so that was not very helpful. I ended up spending a while on installing the fan, and also got a sore thumb.

    I found that the best way to test if the HSF is installed correctly is to tug on each of the four pins. First pull lightly, then increase your force. Rest your hand overtop the HSF so it won't fly somewhere when you pull the pin. If installed correctly, the HSF should not budge at all even when you apply all (or most) of your full strength on pulling each of the pins.

    Hope I helped! :)
  5. genesis211

    genesis211 TS Rookie Topic Starter

    I was able to get far enough into the Bios and saw that the cpu temp was climbing to 92 deg. then shutdown. Do I just need to mount the fan right onto the cpu, no grease or anything? I applied some thermal tape onto the cpu cover itself, not sure if I was supposed to do that. I really don't like the design of the fan, I have always hated those clips. I will keep messing with it.
    THANK YOU for all of your help!
  6. Grafficks

    Grafficks TS Rookie Posts: 302

    Ouch! 92 degrees..

    And no, don't try mounting the fan right on the CPU. There must always be some type of grease or pad between the heatsink and the CPU. This is because the surface of the CPU and the surface of the heatsink are solid. No matter how flat or smooth they are and no matter how hard they are pressed against each other, there will always be microscopic air pockets between them which prevents full heat transfer. A grease between them solves this issue, so you never start a computer without a CPU fan, or without any thermal compound on the CPU.

    What do you mean by "thermal tape"? What is it? Where did you get it?

    You should install it correctly sooner or later after messing around with it some more.

    I also found that pushing down on the center of the fan itself helped a lot too. Lay your hand on the center of the fan and fasten the first pin onto the motherboard. While keeping pressure on the center of the fan (to push it down and keep it down), fasten the pin directly diagonal to the first pin. Always remember that if you feel that you are applying too much pressure on the motherboard at any particular moment, loosen up a bit.

    Best of luck!
  7. Sharkfood

    Sharkfood TS Guru Posts: 1,019

    The problem is indeed the stock Intel heatsink/fan.

    You have to press the four plastic thingies into the motherboard *THEN* crank those babies down with a flat-head screwdriver to almost motherboard-snapping level to get the thing affixed properly.

    At this stage though, I'd say head to your local PC shop (Comp USA or Best Buy if you're in the US) and pick up a tube of Artic Silver 5 (like $10 retail stores) and some isopropyl alcohol. Remove heatsink/fan and clean both with the alcohol.. then apply as-per instructions on Artic Silver's website... THEN crank that baby down with the better thermal compound.

    I've put together a couple Core 2 Duo systems in the last week and both with the stock HS/Fan (not my systems!). Both needed almost-motherboard-snapping emphasis on seating those stock Intel fans down correctly else 70C idle and will climb to 90+C in the BIOS in seconds.
  8. Sean

    Sean TS Rookie Posts: 100

    Well, once you put the hsf into place, did you remove it and reposition? Because if you do that the thermal pad is ruined, and you should go out and get some good paste.
  9. Tedster

    Tedster Techspot old timer..... Posts: 6,000   +15

    thermal tape is crap. Use a good thermal grease like arctic silver.
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