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Newly built computer not powering on

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January 6, 2012 12:23:56 AM

Hello,
This is my first computer build so please bear with me for this one. first my components are:
asus p8p67-mpro motherboard
intel i5 2500k cpu
2x6gb corsair memory
evga gtx 560ti video card
corsair tx 650watt psu

When I first connected all components for a test boot I was receiving power to the whole motherboard and pressing the power button would power on the fans for approx 2-3 seconds before it would shut down. After checking and double checking and redoing all connections when I press the power button nothing happens at all. Any suggestions for me?
January 6, 2012 1:37:10 AM

Check your psu if you have any lights showing that it is on and do a MemOK on your motherboard to see if your ram is causing a problem. check your connections from psu to mobo and mobo to case.
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January 6, 2012 1:42:39 AM

Im gettin power to the MOBO now and when i short the power on pins with a screwdriver the cpu fan starts to spin for maybe 1 second then stops. any ideas with that?
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January 6, 2012 1:54:55 AM

gstowall said:
Im gettin power to the MOBO now and when i short the power on pins with a screwdriver the cpu fan starts to spin for maybe 1 second then stops. any ideas with that?

Try to plug the mobo to the case and use the power button to see if that will do any thing different. Are you able to do a MemOK test on the mobo?
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January 6, 2012 2:16:31 AM

I plugged into the case and am getting the same result. I cant do a MemOK test as it will not stay powered on long enough.
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January 6, 2012 2:57:45 AM

gstowall said:
I plugged into the case and am getting the same result. I cant do a MemOK test as it will not stay powered on long enough.

Mobo might be bad and need to get a new one.
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January 6, 2012 3:00:43 AM

Jiggle the cords around a little then try
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a c 122 B Homebuilt system
January 6, 2012 1:29:01 PM

When you are asking for help, always start off with the system specifications. The
However, onward to some systematic troubleshooting techniques.

Work systematically through our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-postin...
I mean work through, not just read over it. We spent a lot of time on this. It should find most of the problems.

If not, continue.
The following is an expansion of my troubleshooting tips in the breadboarding link in the "Cannot boot" thread.
http://www.tomshardware.com/forum/261145-31-read-postin...

I have tested the following beep patterns on Gigabyte, eVGA, and ECS motherboards. Other BIOS' may be different, but they all use a single short beep for a successful POST.

Breadboard - that will help isolate any kind of case problem you might have.
http://www.tomshardware.com/forum/262730-31-breadboardi...

Breadboard with just motherboard, CPU & HSF, case speaker, and PSU.

Make sure you plug the CPU power cable in. The system will not boot without it.

I always breadboard a new build. It takes only a few minutes, and you know you are putting good parts in the case once you are finished.

You can turn on the PC by momentarily shorting the two pins that the case power switch goes to. You should hear a series of long, single beeps indicating memory problems. Silence indicates a problem with (in most likely order) the PSU, motherboard, or CPU. Remember, at this time, you do not have a graphics card installed so the load on your PSU will be reduced.

If no beeps:

Check for line power at the PSU input. Extension cords, power strips, and power cords do fail.

If you have power and no beeps, suspect components in likely order are PSU, motherboard, and CPU.

Running fans and drives and motherboard LED's do not necessarily indicate a good PSU. In the absence of a single short beep, they also do not indicate that the system is booting.

At this point, you can sort of check the PSU. Try to borrow a known good PSU of around 550 - 600 watts. That will power just about any system with a single GPU. If you cannot do that, use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.

The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.

You can turn on the PSU by completely disconnecting the PSU and using a paperclip or jumper wire to short the green wire to one of the neighboring black wires.
http://www.youtube.com/watch?v=5FWXgQSokF4&feature=yout...

A way that might be easier is to use the main power plug. Working from the back of the plug where the wires come out, use a bare paperclip to short between the green wire and one of the neighboring black wires. That will do the same thing with an installed PSU. It is also an easy way to bypass a questionable case power switch.

This checks the PSU under no load conditions, so it is not completely reliable. But if it can not pass this, it is dead. Then repeat the checks with the PSU plugged into the computer to put a load on the PSU.

If the system beeps:
If it looks like the PSU is good, install a memory stick. Boot. Beep pattern should change to one long and several short beeps indicating a missing graphics card.

Silence, long single beeps, or series of short beeps indicate a problem with the memory. If you get short beeps verify that the memory is in the appropriate motherboard slots.

Insert the video card and connect any necessary PCIe power connectors. Boot. At this point, the system should POST successfully (a single short beep). Notice that you do not need keyboard, mouse, monitor, or drives to successfully POST.
At this point, if the system doesn't work, it's either the video card or an inadequate PSU. Or rarely - the motherboard's PCIe interface.

Now start connecting the rest of the devices starting with the monitor, then keyboard and mouse, then the rest of the devices, testing after each step. It's possible that you can pass the POST with a defective video card. The POST routines can only check the video interface. It cannot check the internal parts of the video card.
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January 6, 2012 1:44:47 PM

^What he said

To be honest it sounds like a PSU failure to me. Make sure you have plugged in all of your system cables, including the 4/8 pins near the CPU fan. In addition, might want to check your local computer store for one of these puppies:
http://www.amazon.com/Power-Supply-Tester-2-0-20/dp/B00...
Really handy tool. On the slim chance you have a PSU laying around... or a friend does... try swapping that in.

However, this could also easily be a motherboard issue :( 
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January 6, 2012 2:07:57 PM

Have you reseated the CPU and checked that none of the pins get bent? Can you try booting without Hard Drive, CD ROM, Video Card, Sound Card disconnected.?

More details on your build would help... check to make sure you connected your Case's Front Panel connectors properly(sometimes they get reversed)

Guessing DOA motherboard or PSU.
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January 6, 2012 4:21:31 PM

PSU is fine, guessing its a MOBO issue. Gonna work on getting another one to test my theory. Thanks for all the great advice/help.
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!