Problems with brand new build

newbbuilder

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Apr 28, 2008
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Hi everyone, This is my first time posting on a forum for help, so please excuse me if I leave out what is usually expected information about the problem i'm having, but anyway, here's what I am encountering.

I just got in a bunch of new parts to build a new PC and I ran into a couple snags once I had everything plugged in and ready to go. The components consist of:

Intel Core 2 Duo Q6750 2.66Ghz
Gigabyte P35-DS3L-S3L motherboard
XFX GeForce 9600GT
OCZ DDR2 800Mhz dual channel ram
Corsair VX450W PSU

Basically the issue at hand is when everything is all connected together and I go to turn on the power, nothing happens, not even the PSU fan will kick in. However, when I disconnect the 4 pin, 12v plug for the CPU, I can fire up the system and things happen. Fans start spinning, including the CPU fan which is still connected to the motherboard, there's a quiet and quick 2 beeps, but since there is no power to the CPU I don't get a post or anything, just a black screen with my monitor light blinking at me (but it doesn't give me a check signal message). I've tried reseating the CPU a number of times, as well as doing some PSU tests. I've also disconnected everything and retied it all back together, but I still encounter the same the same problem when the 12v connector is plugged in, absolutely nothing will turn on. I'm personally at a loss of what to do next or which parts I need to RMA as i've never had this sort of thing happen before. I would appreciate any ideas or other things to try that I may have missed. Thanks for your time guys, hopefully I can get this issue resolved soon.
 

beurling

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Jan 2, 2008
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first thing that comes to my mind is that you have insufficient power for your system. When it doesnt have to power the cpu it works fine, so the PSU can't be broken. But 450W should be enough, unless I'm behind the times a little bit.

My 620W runs my system fine, but I don't even have a quad core.

If at all possible, try hooking up another PSU. If that's not an option, then I would either replace your PSU, or replace the Motherboard. One of them isn't working properly. (PSU in my opinion)
 

lcaley

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Nov 19, 2007
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Have you tried keeping the CPU power in and unplugging the PCIe from your 9600GT? I believe (its very possible I'm wrong about this) that the card will still run the monitor without the power, it just won't play games or anything. But either way, even if the machine doesn't POST, if it turns on, you'll have a better idea that its a PSU issue, and not the motherboard.

It could be a defective PSU and isn't really putting out 450W, because that should be enough.
 

gow87

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Mar 22, 2007
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Well 450W PSU is enough however i dont know how efficient it is? but imagine if its 90% efficient thats 405W of power. if you have a few HDD's they can draw upto 30W on boot up, cpu will be over 100, ram and intel chipset will draw a fair amount. generally try unplugging HDD's and CD drives and try again see if it will power up. other than that swap testing is the way forward but obviously you need something to swap
 

boonality

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Gow87, from how I understood power supply efficiency was that you drew the extra percentage from the wall. IE your power supply used more power than it produced, but could still achieve the rated max. Rather than drew the rated max from the wall and produced less based on it's efficiency. Either way it doesn't matter for this post. was just something that hit me reading through the thread.
 

newbbuilder

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Apr 28, 2008
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Thanks everyone for all the quick replies and ideas to try out. First thing; I do have standoffs spread out between the case and the motherboard, and I have tried it outside of the case sitting on a clean piece of cardboard, it yielded the same results. Second, I attempted to remove the power cables to everything except the 24 pin ATX to the motherboard and the 4 pin for the CPU. I came across the same problem, hit the power button and no juice. So i'm going to conclude that the issue at hand is in the motherboard now since even when nothing else but the board has power cables connected to it the system still isn't booting up. Again thanks for the quick tips, it is much appreciated.
 

roadrunner197069

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Sep 3, 2007
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I wouldn't RMA a mobo until you test the PSU. If you dont know how or feel comfortable take the PSU to a shop for testing. The 24 pin has 12v 5v and 3v connections. If one is bad it wont post. A bad PSU is more common the a bad mobo.
 

Mondoman

Splendid
OCZ RAM sometimes doesn't work at the default standard 1.8V for DDR2 RAM. Try installing only 1 stick of RAM; if that doesn't work, try installing only one stick of RAM rated at 1.8V (hopefully, without having to buy one). Once you get the system to boot, you can adjust the RAM voltage in the BIOS.

 

newbbuilder

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Apr 28, 2008
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I would think though that if it was the ram, that even if I took it all out the system would still at the least fire up. However even without any of the ram sticks in as long as I had that power cord plugged into the CPU nothing at all works, not even the PSU fan. After work today I'll try to see if the new PSU can and will fire up my current system. As for PSU testing, I've visited the Corsair website, and tried out the method of shorting out the PSU with a paper clip (green to black, tried all the blacks) and it works fine, runs the case fan and all that jazz. I mean, unless maybe it's a bad CPU and the system is running on a failsafe to not fire up in order to prevent further damage to the components then I really have to think that maybe the 4pin was damaged/faulty.