Newly built system reboot itself every 3 sec.

spambox

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Mar 3, 2007
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Hi I am new in this forum. I just built my new desktop. But when I tried to start the machine for the first time, it kept rebooting itself. The fan in the chassis start to rotate, same as the PCI-E video card. The CPU fan try to start but only move a little bit then stopped. So it didn't not really start rotating. Then after 4 seconds, everything start over again.
I tried another 500W power but the problem remains. I disconnect the fan in the rear of the case, and take off the PCI-E video card. The problem remains. I can hear the sound of the CPU when it tried to start, but still it reboots itself again and again.
BTW, I used C2D 1.86g, Gigabyte 965P-DS3 rev 3.3 which support 1333 FSB, EVGA 7600GT video card and PNY DDRII 667 2G Memory.
Any clue will be greatly appreciated!
 

GSTe

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Is the CPU fan plugged into the motherboard correctly?

No cables catching the fan?

PSU cables (including the 4 pin) plugged into motherboard correctly?

Heatsink/fan properly seated? Plastic 'legs' clicked into place?
 

spambox

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I just used the stock heatsink and fan. I will say positive on all the questions. I tried to remove the memory and with or without it, the sympton are all the same. So my guess is the memory problem. The mother board totally does not recognize the memory.
Is my guess reasonable?
 

GSTe

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The CPU fan should rotate even if the memory doesn't work, though faulty RAM could cause your system to reboot ad infinitum. Can you get into the BIOS? If you can, then there should be an option to stop the PC rebooting after failure.... if you can do this then you should get an error code. Also would be an idea to check the Gigabyte website and see if they have a list of memory that's compatible with your motherboard.
 

spambox

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Hi GSte, thank you for your information. I just can not get into BIOS because it restarts every 3 sec. It is so short that only the fan start a bit. The CPU fan tried to start a little bit but immediately stop in half sec. Other fans start for 3 sec then stop. That's why I totally have no clue where the problem could be.
 

korsen

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Let me just ask this simple question... Do you know what standoffs are?

I didn't once, and my pc rebooted after displaying the mobo logo into eternity.
 

spambox

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Sorry, I only know that standoffs are the stuff that separate one from the other to keep from short cut for example. But not any more.
My problem now is that the reboot is so quick (3sec) that no signal ever send to the monitor. That's why I can not see and error message to further identify the problem.
 

spambox

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Yeah, maybe that's the problem. I once put the heatsink on the CPU and couldn't stick the for legs into the motherboard, then I removed it and tried again. I noticed that there are some paste left on top of the CPU. Will that be any problems if I just put the heatsink back and stick it into the motherboard. Will it affect anything? But I am sure all the four legs are firmly sticked into the wholes.
BTW, ever since the first time I start the CPU, I met the problem. Is it possible that the CPU get overheated right after 3sec and cutoff itself?
I am a newbie, so forgive me for any silly questions.
 

wallis

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this is a well documented problem with this mobo and memory and SPD settings...the problem usually occurs when your mobo sets the memory voltage to 1.8v (JDEC standard)when in fact the memory requires 20, 2.1 or even 2.2v to operate correctly.

check to see what voltage your ram is supposed to run at.

remove 1 stick of ram go into bios and set the vdim voltage correctly.

reboot and see if it remedies problem

some people have had to buy a cheap stick of ram in order to get into bios to set the voltage correct.

these problems where mostly solved with later bioses...after F3 i think...what bois version do you have?

dont up the voltage if your ram isnt specced to do so

this thread should help you
http://forums.overclockers.co.uk/showthread.php?t=17636047
 

spambox

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Wallis, thank you so much for your reply. My mother board should be the latest version which supports 1333FBS. So I assume it should have the latest BIOS.
I will try to find some standard memory to get into the bios.
 

wallis

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just a cheap stick that you know will work at 1.8v and 5-5-5-18 which is the JDEC standard.

most performance ram needs more voltage and will not always work at the JDEC standard of 1.8v.

also removing battery and clear cmos with a jumper wont do any harm
 

wallis

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good luck with that....look in the box of your normal ram to see what voltages it is specced at.

on mine there is a sticker saying mine must be set to 2.1v. so i had to go into the bios and set vdimm voltage to +0.3.

do not up the voltage if the ram isnt specced to be raised or you could damage it.

i looked on pny's website for the correct voltage for your ram but it didnt say.

if you cant find out the voltages i would wait untill you can...but trying your mates ram will help eliminate sources of your problem

good luck
 

mike2077

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Try one stick in each of the slots by itself. Then try the other one. I had a similar problem due to one of my sticks being dead, it wouldn't post. The good stick let me post and everything worked fine afterwards. Whenever I tried pluggin the other stick in any slot it would constantly reboot.
 

spambox

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Hi Wallis, you are so right. I tried to clear the CMOS and remove the CMOS battery. Magically, it works. Now it is running and I am installing my Vista Ultimate.
Thank you so much for everyone's help!