Unknown problem with new build

[lixah]

hey guys, i recently built myself a new computer, its been working for around 3-4 days, i often leave it on overnight, and this morning i woke up to find it off, and it won't boot up, there is a standby light on, on the mobo, but it wont even attempt to boot, no fans spin or anything when you press the button.
my build was a;
xfx 790i ultra sli
g skill ripjaw (2x2gb)
Hd 5850
coolermaster GX 650W

its been running smooth untill now, and i cant imagine what is wrong, any help is appreciated.

-Lixah

 

[eloric]

Since it is a new machine then something could have worked its way loose. For example the CPU fan, if not connected, may prevent the system from starting. The other possibility is that there is a bad component that took a few days to go sour. If that is the situation, then you will need to find it.

Here are the simple things to start with:

Have you powered down the PSU so that the standby light goes off for at least 30 seconds?

Have you reset the CMOS? Your motherboard manual will tell you how to perform this step.

Have you read the "System won't boot" and "no video output" checklist? This is for brand new builds that do not post so many of the steps do not apply.

Do you have a speaker on your mothorboard? If not, step 16 has a link to get one - your local parts store may have one too, and they are only a few dollars. The sounds from this speaker may give you a hint, and you will want one to verify that you have solved the problem.

Don't just dismiss a step because it worked before - step 17, for example, describes the front panel plugs. Disconnect them and attempt to restart your machine to see if you found a short. If the problem persists, reconnect and move on to the next component.

The bad news is, you are going to have to tear down and rebuild your computer until you find the issue.

The good news is that your build is all fresh in your mind. Also, when you complete this process, you will never have to take a computer to some rip off repair joint ever again. Ok, so it is only a small consolation. Try to keep a positive attitude and think of it as a good practice session.

Good luck.

 

[lixah]

ok, thanks alot for the reply , i will try this. however i wonder if the problem might be the cpu, since i put the cpu togher with my old pc components to check it, and exactly the same thing happened, nothing, it just sat there, made no noise, the fans didnt try to spin or anything, so i wanted to ask, is this the kind of symptoms for a dead CPU? by the way, all the components i tested the cpu with are known to be working, since i was using almost all of them in my old system : )
also if its any help its a Q6600 CPU.

 

[eloric]

You might have found your problem. Do you have your old CPU that you could put into your new components? That would verify for sure.

 

[lixah]

i do not, the cpu was one of the few components i took from my old build

 

[lixah]

my local pc shop is asking 15£ to diagnose it, i thought this sounded good, is it?

 

[lixah]

i tryed all these solutions, and nothing, if it matters there is a standby light on, on the mobo, does this mean that i can eliminate the PSU failure?

 

[eloric]

How old is the CPU? Is it still under warranty? You might try to RMA that. If you replicate the problem in a known working system, you generally have the issue solved.

 

[lixah]

im not sure tbh, im 90% it would be out of warranty by now though, since it must be ... 4 years or more, i would guess.

 

[lixah]

i think i will take my system to the local pc shop, 15£ to know what the problem is seems like a good deal to me,

 

[jsc]

Although CPU failures do happen, they are very rare.

Work through our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-posting-boot-problems
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.

I have tested the following beep patterns on Gigabyte, eVGA, and ECS motherboards. Other BIOS' may be different.

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

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.

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:
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=youtube_gdata

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.

 

[lixah]

Hello, thank you for your relpy, i just have a couple of questions, i prosume i can 'breadboard' while the mobo is inside the case? also, im trying to test the first thing, where i just have the CPU/HSF plugged in, but i prosume i need both the 8 pin and the 24 pin power connectors plugged in? i tryed this, and allthough the power led was on, it did not make a sound

 

[lixah]

i have just checked the psu, and am 100% sure it is working fine, so the problem is elseware

 

[lixah]

i found an intel pentium 4 CPU in a very old pc, will this fit my 790i mobo? so i can check if that is the culprit.

 

[lixah]

just spoken to the shop testing my computer, they told me that the motherboard is dead. so can anyone suggest a new one ?