Help - My first build is not working

[NexusVan]

Hello,

So I've recently bought and assembled my very own first PC.
Today I was finally done and connected it to the power.

At first I touched the metal part of the case while barefooted and could feel electrical current, I then immediately switched my power supply off.

This doesn't seem normal to me, I know I touched the metal part of the case but shouldn't that be grounded?

Seeing that I've already encountered this with my other PC (which had PSU issues so I thought it'd be gone with the new one) I switched the PSU back on.
Tried to turn on the PC and.. nothing.
No lights, no fans, I can't even see a light indicator on the motherboard (not sure if there is one though).

I have a Z77X-D3H mobo and a Seasonic X760 PSU.
This is how the PSU looks on the connectors side: http://www.jonnyguru.com/modules/NDReviews/images/SeasonicSS760KM/DSCF3189.JPG

The PSU came with a 20+4 pin ATX connector. On the PSU's end it is split with a 18 pin and a 10 pin - I connected them both.

My motherboard has a 4-pin ATX 12v connector for CPU so I used the 4+4 pin connector and connected only one of them, other one is left hanging. On the PSU's end its a 8 pin.

Rest of the things I connected are 3 sata (2 hdd + optical drive) and a molex for fan controller. I didn't assemble my graphics card yet.

Can someone please tell me what could be wrong or what is already very wrong?

 

[InvalidError]

If you feel an AC tingle when touching the computer case which is supposed to be grounded through its power cable then it means you have a floating ground somewhere and leakage current is electrifying the case.

If you have a voltmeter, you can identify a floating ground by measuring the voltage difference between neutral and ground. The difference should ideally be 0V AC but if you are feeling the voltage, you will likely measure more than 30V AC since it takes around 40V to feel voltage through normal skin.

The open ground could be:
1) missing/broken connection between the power connector's ground pin to the PSU's case inside the PSU
2) bad ground connection in the power cord at either end
3) bad ground in the outlet
4) bad ground elsewhere in the home/apartment wiring
5) bad building ground

Changing PSUs will not auto-magically fix building wiring faults.

 

[chugot9218]

Make sure you have the correct plugs into the MOBO (someone posted once and said they had the PCI power into the MOBO which I didn't even think would be possible...), and make sure you have the standoffs in.

 

[NexusVan]

Thanks for your replies.

Make sure you have the correct plugs into the MOBO (someone posted once and said they had the PCI power into the MOBO which I didn't even think would be possible...), and make sure you have the standoffs in.

9 standoffs in place, the motherboard connector I used is the right one:
http://www.tomshardware.com/forum/311628-28-connecting-power-supply-mother-board

@InvalidError

Unfortunately I don't have access to a voltmeter.

As for faulty grounding in the building - might be. I tried changing power cord and a power outlet, also tried connecting directly to the power outlet but still I can feel the current.

update: I just checked my other PC using the same cables and power outlet. At least this time I didn't feel any current touching the case (replaced PSU lately if that's related).
Hmm, does that mean I must have a short circuit in my new PC?

Looking into your suggestions now

 

[NexusVan]

Is there a way I could test my power supply to see if it's faulty?

 

[InvalidError]

Hmm, does that mean I must have a short circuit in my new PC?

PSUs have some power filtering and surge suppression components on the AC line that may include capacitors and MOVs between live and ground. If you have a faulty ground, those filtering components can leak AC voltage to ground which you would feel as an annoying but harmless tingle. This still needs to be addressed properly by fixing the home wiring because should the neutral wire ever break somewhere in the home wiring or PSU, the case would then come up to full live and potentially lethal voltage.

If there was an actual short between live and ground within the PSU with a floating ground in the home wiring, you would not be feeling a mere 'tingle', it would be an extremely unpleasant nasty/sharp and potentially lethal jolt.

Your other PC may not feel "tingly" simply because its PSU does not have any filtering components between live and ground, which gives you a fake sense of security until the day where live voltage finds its way to the non-grounded PC case and zaps someone.

With working ground wiring, short of a lightning strike in your immediate neighborhood, you should not feel anything. Ever.

 

[NexusVan]

PSUs have some power filtering and surge suppression components on the AC line that may include capacitors and MOVs between live and ground. If you have a faulty ground, those filtering components can leak AC voltage to ground which you would feel as an annoying but harmless tingle. This still needs to be addressed properly by fixing the home wiring because should the neutral wire ever break somewhere in the home wiring or PSU, the case would then come up to full live and potentially lethal voltage.

If there was an actual short between live and ground within the PSU with a floating ground in the home wiring, you would not be feeling a mere 'tingle', it would be an extremely unpleasant nasty/sharp and potentially lethal jolt.

Your other PC may not feel "tingly" simply because its PSU does not have any filtering components between live and ground, which gives you a fake sense of security until the day where live voltage finds its way to the non-grounded PC case and zaps someone.

With working ground wiring, short of a lightning strike in your immediate neighborhood, you should not feel anything. Ever.

Thanks for your reply, I wasn't sure what are the implications of running a PC, or any electrical device for that matter, under those terms. I will look into it as soon as my electrician guy answers his phone. I do have a somewhat cheap PSU on my other PC so your scenario seems to fit.

Other than the unpleasant side-effect of being electrocuted by my new PC there's still another problem else my PC should be running. I think either the PSU or the motherboard is faulty but I'm only guessing since I don't have much experience in neither.

I have connected everything properly and was careful doing so. I followed the motherboard manual in every step to make sure everything is connected as it should but there is still no indication of power.

Can you please help me isolate the issue?

 

[knightdog56]

Please let us know what you find out about the wiring!

 

[InvalidError]

The usual recommendation for "no-boot" on new build is to run through the THG troubleshooting guide.

However, with a floating ground issue like you seem to be having, touching any component inside the PC may cause the leaking AC voltage to damage (more) components so I would recommend against doing 'breadboarding' or anything else that may cause you to touch components while the 'tingle' is on.

 

[NexusVan]

I was able to run my PC last night, it turns out the motherboard's 24 pin cable wasn't fully secured and that's the reason it didn't receive power. PC is up and running and proves to be stable.

@InvalidError: Thanks for shedding some light on the grounding issue, it wasn't clear to me what could cause this. For now I am running the PC with the AC leakage though I'm careful and after the weekend hopefully I'll get the wiring checked out.

 

[NexusVan]

Best answer selected by NexusVan.