Hi people,

I just got my son a new desktop machine for Christmas, but the damn thing won't boot. At all. It never even gets as far as sending an image to the monitor.

Now, I had the thing custom built, and I can tell that the people who put it together weren't paying a great deal of attention, since the front fan in the cabinet wasn't even hooked up.

Here are the specs:
CPU: Athlon x4 640
MB: Gigabyte GA-970A-DS9
GPU: Gigabyte GVN640OC-2GI
HDD: Seagate Barracuda 7200.12 - 3.5"
RAM: Kingston ValueRAM - 8GB DDR3 1333MHz PC3-10600 CL9
PSU: Energon EPS-750W CM

The first thing I noticed was that the CPU fan wasn't switching on. I've tried moving it to a different fan port, and that works, but the machine still doesn't boot. I've also tried removing the RAM stick, since that supposedly should give me a warning beep on boot, but nothing. All the fans start and I can hear the HDD spin up, but nothing more happens.

Could it be that the CPU_FAN port on the MB is broken (well, it certainly seems to be) and that the MB won't boot if it doesn't register power being drawn from that port?

One thing I haven't tried yet (because I'd like to avoid it if possible) is to move the graphics card into my machine to see if that's what's wrong. I think it unlikely though. The fact that the CPU fan doesn't switch on when connected to the CPU_FAN port seems to indicate that there is something more fundamentally wrong than that.

Any ideas are welcome.

Sounds like a faulty MB and no testing by the builder.

Your also right most MB's wont boot without draw on the CPU fan pins to keep your CPU safe

Yup, when the machine won't boot at all, high chance it's related to CPU fan.

If you are not getting any power at all theres a few things I would check first off :

Check the block of cables that control the USB, Power switch and hard drive lights. The diagram is in the motherboard book.

Next up is make sure the additional power lead is connected to the motherboard, the smaller 4 pin one.

Finally make sure that the 24 pin ATX main power block is connected the the motherboard correctly. Sometimes when plugging this in the metal connectors can be pushed up so there is no connection, it can also happen with the molex power leads that go to the different devices.

Finally, just a daft one, try changing the power lead (kettle style lead) that goes into the exterior of the PSU then to the wall socket

Yep, sounds like a foulty board. I guess whomever built your new rig didn't bother hitting the power button.

But I am. Everything is switching on, except the CPU fan. The PSU, the GPU fan, both cabinet fans (now that I've connected the front fan) and the HDD all spin up. So does the CPU fan if I connect it to the SYS_FAN1 port, so it's not the CPU fan itself that's the problem, it's definitely the CPU_FAN port on the MB that's not delivering any power. I already did. Whoever put the thing together had wound all the cables around each other in a tight coil, probably to minimize the space they took up, but when you need to mess around with the cables that's not so practical, so I unplugged them all, unwound them from each other and plugged them all back in. Sadly, it made no difference, so I assume they were also connected correctly before. And yes, I did refer to the diagram in the manual a bit, but the layout is also printed on the MB itself. Already did that. It is. Do you really think this is likely? I mean, I'll happily do it, but everything that needs power seems to be getting it, except for the CPU_FAN port, and I doubt it has its own cable to the PSU. Hehe, no. There's definitely power coming to the PSU. I am 100% certain that is not the problem. The problem is that simply hitting the power button wouldn't be enough if you were inattentive. I mean, the machine seems to turn on. The power LED would have turned on, and he would have heard both the PSU fan, GPU fan and rear cabinet fan, as well as the HDD.

If what he was after was simply "is there power?" and then switched it back off immediately, then he could have easily missed it. Of course, the Blue-LED front fan wasn't hooked up, but I got them to put that in as an extra, it wasn't part of the standard loadout.

Still, if it was me selling custom built PCs, I'd make sure that, as a minimum, they could boot and I could access the BIOS, but that would of course require hooking it up to a monitor and a keyboard. I know the shop I ordered it from was hellishly busy before Christmas, and also had delivery problems with some of the components (I had ordered a dual core CPU which they couldn't get after all, so they put in a quad core instead, free of charge, and I just discovered that the 650W PSU I ordered has been replaced with a 750W one), so I imagine that's a kind of explanation for their less than stellar quality control, although it's certainly no excuse.

Don't worry, all consumer electronics sold in Denmark have a 2-year warranty by law. I'm not concerned that I won't get it to work ever, or that I'll have to buy new hardware to replace the faulty bits. I'm just annoyed that my son can't use his Christmas present in the foreseeable future, since it's the holidays and everything is closed, and when I do bring it into the shop, I'm afraid they'll keep it for a couple of weeks before I can get it back.

Hence, I just wanted to be absolutely sure my suspicions were correct, because if I bring it into the shop and they say "oh, you just have to move this jumper", then I'll kick myself, hard!

Oh, and I did check that the "clear BIOS" jumper wasn't attached.

I would also suggest you check the monitor connections both at the monitor and at the box. Light should go from orange to blue (depends on the monitor) if the card is sending a signal. Might even hook up another monitor to be sure.

Not saying it's the monitor but I have run into a couple of bad ones over the years so it's worth checking out . . . =)

I can add that if you have tried removing RAM and get no beeps the problem isn't with the video card which gets initialized afterwards.

Well, from my experience with MBs not every board starts the CPU fan when you switch on the power. And it may not be really that suspicious, that the fan works when plugged into different connector. If BIOS has something like Smart Fan or whatever they call it depending on a manufacturer, it may very likely be working when temperature sensor hits the trigger value. Does the CPU heat up even a little after you switch the system off? Is the additional power for the CPU plugged in?
Also, what's a Gigabyte GA-970A-DS9? I could only find the GA-970A-DS3.

Hmm, that's a pity. That opens up the list of possible problems somewhat.
I have no idea. The heatsink is so massive that I can't get anywhere near the CPU.
Yes.
That's what is known, in technical terms, as a "lousy memory" ;-)

You are of course correct, it's a GA-970A-DS3.
I get no beeps no matter what I do :-(
I'll try this tomorrow. I'm not messing any more with it tonight. I've seen enough weird ass fixes in my time to know that something so screwy might in fact work, for whatever reason. I'll let you know what happens.

I'm all excited to hear from you if it worked.

That's because the fault likely lies at one of the core components. Power, Motherboard or CPU. everything else is effectively peripheral. There is the odd exception to this rule where a peripheral component is feeding back power and tripping the motherboard. The only way to be sure would be to remove those possibilities.

If I was to throw money at it though I would say that because the CPU fan doesn't work in the correct slot that the CPU itself is faulty. That might explain why the fan does work properly when attached to a case fan slot.