Help Needed With 1st Boot Up Problem


Aug 17, 2010
Just finished putting the components together on my 1st build and when I hit the power button all of the fans including cpu,psu, and all case fans come on for a few seconds and shut off. After a few seconds they all come back on again and then shut down. Nothing else happens and computer won't boot. This cycle just keeps continuing until power is pulled. Any suggestions would be helpful. Here are my components:

Antec 902
Gigabyte UD3P
ATI Radeon 5770
WD CAviar Black Hard Drive
Intel i5 750
G Skill Ripjaws 8GB (2GBx4)
Asus DVD burner


Apr 9, 2009
Check stupid things..

All cables are plugged in.
Your 4pin power is plugged into the motherboard for your CPU.
Your graphics card(s) are in correctly.
Pull out all RAM apart from one and see if that helps.
Unplug all USB items and boot without anything but power and monitor plugged in the back.
Check with another powersupply.

Have a search around on these forums.. I can't remember where the thread is - but there's a huge list somewhere of all the common first boot problems. Just search "first boot" in the forums search and see if you can get it.


Work through our standard checklist and troubleshooting thread:
I mean work through, not just read over it.

Breadboard - that will help isolate any kind of case problem you might have.

Breadboard with just motherboard, CPU & HSF, case speaker, and PSU. You do have a case speaker installed, right? If not, you really, really need one. If your case or motherboard didn't come with a system speaker, you can buy one here:

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:
At this point, you can sort of check the PSU. Try to borrow a known good PSU. 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.

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 or long single beeps indicate a problem with the memory.

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.

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.


Aug 17, 2010
Thanks. I have the Corsair 650w and I was able to work through the problem and everything is running great as of now. Thanks for your time and response.


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