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Computer doesn't power on-read the sticky post checklist

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Anonymous
a b B Homebuilt system
October 16, 2010 1:53:37 AM

Hello, I just recently purchased the parts to build a new PC and assembled them all today. This is my 4th build but I concede I am far from knowing everything about building. When I hooked everything up I could not find any light on the MOBO to show that it had power but it's a new one so I assumed it didn't have one. When I press the power button the fans and LEDs spin and light up but the instant I release the button it shuts off. If I hold the button down for a few seconds the PSU sort of clicks and the fan doesn't spin but jerks a bit. The other fans and LEDs appear to sputter or flicker.
I did the test where you short out the green wire on the 24 pin connector to see if the PSU powers up without being connected to anything. It came on just fine. The PUS is not new as is everything else in my system. It worked on my previous system just fine and I am positive it is powerful enough @750W. From what I have read on here it could be a short somewhere but even when I unhook all but the CPU, HSF and PSU it does the same thing. If I can diagnose the problem it won't be too big a deal to replace the parts. I bought them all from newegg so I can RMA and though I would be out the shipping costs its better than being out the whole cost of the part.
I guess it was inevitable that I would run into building problems at some point. They can't all go perfect.

My System:
AMD Phenom IIx3 740 BE
MSI 770-G45 ATX AM3 MOBO
G.Skill Ripjaws Series DDR3 1333 CL7
EVGA Nvidia GTX 460 GPU
WD Caviar Blue 500GB 7200RPM HDD
Cooler Master Real Power Pro 750w PSU


a c 103 B Homebuilt system
October 16, 2010 2:13:12 AM

Have you tried the bread boarding which is in the sticky?
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Anonymous
a b B Homebuilt system
October 16, 2010 3:00:19 AM

I just finished breadboarding. I was a little wary at first because for some reason it seemed a little scary to me to hook everything up outside the case. Here are my result:

Breadboarded Mobo, PSU and CPU-----> Boots with no memory warning beeps.

Mobo, PSU, CPU and RAM-----> Boots with one long beep and 2 short beeps

Mobo, PSU, CPU, RAM and GPU-----> Boots with one short beep after a 10 or so seconds

At this point I put everything back in the case to see if it still works which to me would show a short somewhere in the Mobo tray. Mobo, PSU, CPU, RAM and GPU all boot fine.

I think plugged two of the case fans into the sysfan spots on the mobo----> no boot it actually kind of sputters like how a car does when you're cranking it.

I unplugged one fan and left the other-----> Boots fine

I tried hooking the fans up via the PSU rather than the Mobo and it seems it will not boot with more than 1 sometimes 2 fans hooked up. This leads me to believe that it is my PSU. If I plug in fans one at a time while it's turned on it runs them fine, it just won't boot with more than 2.

I apologize if my long winded post wasted anyone's time here. If anyone has feedback I would very much appreciate it still. If I haven't exhausted all means here I would like to know before I drop the cash on a new PSU.
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a c 122 B Homebuilt system
October 16, 2010 6:40:13 AM

Quote:

Breadboarded Mobo, PSU and CPU-----> Boots with no memory warning beeps. Good.

Mobo, PSU, CPU and RAM-----> Boots with one long beep and 2 short beeps Good.

Mobo, PSU, CPU, RAM and GPU-----> Boots with one short beep after a 10 or so seconds Good.

At this point I put everything back in the case to see if it still works which to me would show a short somewhere in the Mobo tray. Mobo, PSU, CPU, RAM and GPU all boot fine. Good.

I think plugged two of the case fans into the sysfan spots on the mobo----> no boot it actually kind of sputters like how a car does when you're cranking it. OK. We have a problem here.

I unplugged one fan and left the other-----> Boots fine

I tried hooking the fans up via the PSU rather than the Mobo and it seems it will not boot with more than 1 sometimes 2 fans hooked up. This leads me to believe that it is my PSU. If I plug in fans one at a time while it's turned on it runs them fine, it just won't boot with more than 2.

Fans use very little power. One amp at 12 volts will power 3 or 4 fans.

Try each fan separately. You may have a bad fan.
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Anonymous
a b B Homebuilt system
October 16, 2010 7:15:01 AM

I kinda figured the fans would not be drawing much power but would a ban fan really prevent the boot up? I tried connecting all my fans both connecting to the mobo directly and also using the connectors from the PSU. Also no fans it fires right up. One fan it resembles a car starter cranking a couple times before firing up. More than that and it just cranks like a flooded car or a car with a bad starter.
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a c 103 B Homebuilt system
October 16, 2010 1:15:37 PM

When you say one fan do you mean the same fan all the time or are you trying the fans randomly one at a time?
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Anonymous
a b B Homebuilt system
October 17, 2010 1:22:40 AM

I have tried each of my fans as someone suggested a bad fan and all the fans work but only one at a time. Today I also tried to boot with the HDD plugged in but with no fans and....no boot. It just does the same thing that I can only compare to a car engine cranking. Even when I power on with nothing but the PSU, CPU, RAM and GPU it still seems like it struggles to power on. I ordered a new PSU that should arrive Tuesday so we shall see.
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