SUDDENLY Zero Power On Boot Up

KT888

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May 5, 2012
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I am having a sudden problem with my system. When I try to power it on Absolutely nothing happens. No power. Well I shouldn't say NO POWER because the lights on the MB are lit up and I have a USB connecter that has an LED and that is also lit up. However powering on does nothing. POST doesn't even run so it's definitely not a software issue. This system has 3 GPUs, 8 3 & 4TB SATA HD as well as 2x2TB USB 2.0 drives, 5x3TB USB 3.0 HD, 4x4TB USB 3.0 HD.

System Specifics
Intel 4770K
ASROCK Z87 OC Formula/ac MB
Corsair Hydro Series H80I CPU Cooler
Intel 520 Series 120GB SSD Running Windows 7 Ultimate
32GB G.SKILL RipjawsX 4X8GB DDR3-2133 CL9
EVGA G2 1000W 80plus Gold Fully Modular PSU

GPU 1 Gigabyte 7870 OC
GPU 2 Gigabyte 7870 OC
GPU 3 HIS Radeon HD 7770 GHz Edition
Connected to 5x27" monitors and 1x42" Samsung TV

System was running fine for 6 mths then one day it froze and when I attempted to reboot nothing happened which brings me to my opening statement

I sent my original PSU back since they had done a recall on the batch of the particular model I had purchased anyway and I thought that was a logical place to start. When I received the new PSU I installed it and when I booted up my system would look like it was powering on but after about 35 seconds would shut down and reboot and it did this about 8 or nine times. I finally just cut the power to the system and when I tried to reboot again I was at my original situation. Absolutely nothing happening. MB LEDs were lit and the USB LED was lit but nothing happened as far as the PC booting up. I talked to a tech at EVGA because I thought that the PSU had arrived DOA and after I described what had happened the tech agreed that it sounded like the PSU was indeed DOA and even though the LEDs were lit it was likely that the 5 volt rail was working but the 12 volt rail was not. However after getting off the phone with him I decided to try it in one of my other systems and it turned out that the PSU is fine. When I called back to cancel the RMA the tech I spoke with suggested that one of my GPUs may be bad so my question is… from what I have described from your collective experiences would a dead GPU cause the symptoms that I have described because I don’t think so. I’m not sure if this could be a MB issue but I thought I would find out if you folks would have any insights. If I am unable to get any helpful insights from the technically savy folks on Toms I guess I will have to troubleshoot each component of my system but I would really prefer to not pull it apart because with so many components in it it is a real pain to do that. The worst being all the cables are behind my MB due to cable management and I’m sure you can guess how many cables there are with all the drives in this system and 3GPUs (I’m sure a lot of you know what a pain it is to completely pull your system apart and start from scratch)
So if any of you have any experience that may be helpful to me I would be extremely grateful for your assistance.
 
Solution
Yes, and because both Psu`s exhibit the same same function.
First power up and a lock out.

It is detecting a short circuit.
Protecting and damage a short circuit or, circuit load that will end up taking other devices with it.

In other words a 12v load on a circuit will no where to flow would heat up due to resistance causing a fire for example.

So it jumps to ground and is Isolated till the point of resistance is removed. or voltage is not detected on the earth or ground of the circuit.

Ground is a negative current so if a plus crosses it
It a jump in the natural path of a circuit.
Meaning it has a fault.

Consider this, if your electrical ring main tripped.
when you plugged something into the wall.
You reset the trip switch and...
Yes a Dead Gpu, or a fault with a graphics card would stop the system posting.

You have a 1000W power supply, an as you know they are not cheap.
So it incorporates a lot of protection features.

One of them is short circuit protection.

If for example a card or a Gpu is no longer working it is classed as a short circuit.
Because the electrical current does not flow along the path intended due to a failed part.

And any resistance due to a non working part or circuit. Or a large enough positive charge sent to earth or ground is a trigger for a short circuit protection feature of a PSU.

In the same way as in your house if a trip switch box is used if a + volt is sent to earth, it trips the whole house or the circuit that grounded.

Until you reset the trip switch in the main fuse box for the circuit. Providing the device was removed from the circuit that caused it to turn off.

Normal power in the circuit is resumed.

On a psu the circuit acts the same.
But in order to reset it. The protection circuit lock out, or trip switch internal to the Psu.

You must first turn it off at the rocker switch of the Psu. Remove or switch off from the plug socket.

Count ten seconds, turn the socket switch on.
Then the rocker switch on the Psu back to normal state.

Resetting the locked, or tripped circuit


 

KT888

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May 5, 2012
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That makes a lot of sense.

But then why the difference in behavior? First PSU no power, New PSU tried to boot up and then suddenly no power again.

By the rocker switch you mean the power switch on the back of the PSU right?
 
Yes, and because both Psu`s exhibit the same same function.
First power up and a lock out.

It is detecting a short circuit.
Protecting and damage a short circuit or, circuit load that will end up taking other devices with it.

In other words a 12v load on a circuit will no where to flow would heat up due to resistance causing a fire for example.

So it jumps to ground and is Isolated till the point of resistance is removed. or voltage is not detected on the earth or ground of the circuit.

Ground is a negative current so if a plus crosses it
It a jump in the natural path of a circuit.
Meaning it has a fault.

Consider this, if your electrical ring main tripped.
when you plugged something into the wall.
You reset the trip switch and straight away it flipped off again.
What you you suspect it was that caused it to flip off again. the device you plugged in or connected is faulty.





 
Solution

KT888

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May 5, 2012
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Thanks very much for your descriptive explanation shaun o.
Can you explain to me what was going on when the system was rebooting over and over and over again 9 times before I unplugged the power?
Why did the PSU behave differently in that situation?
And then not even try to boot when I rebooted after unplugging the power.
 
Because believe it or not the system goes through a series of tests.

Example Is memory there, yes- set the speed.
Ok

Check cpu, is cpu type model reported, yes, set on stepping and default speed setting.

Are the graphics card slots Pci-e poplulated.
No.

Restart test. boot loop.

In most cases it is because it cannot obtain the values, or settings of a device.
If the problem persists.

Again till you resolve the problem by setting the bios of the board back to base settings.
Or removing and inspecting the device or devices for damage or non functioning.

But the cause of a boot loop with no error messages audio, or by on board led readout can relate to a hardware device that is dead.





 

KT888

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May 5, 2012
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smile. Thank you Shaun o I am quite familiar with the POST process. I was just wondering why in that instance POST was running but that behavior changed and POST ceased to run when nothing had changed.
I was just wondering if you knew exactly what was happening IN THERE.
I thought you might because of your very good descriptions of the PSU protection behavior.
 

KT888

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May 5, 2012
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Shaun o
I guess I'm not clear on how to reset the PSU once it fails the first time. I switched off 2 of the GPUs from the MB. (The OC Formula has an actual switch that you can turn off each of the 4 PCIe slots) Turned on the system after I had reinstalled the G2 PSU in this system and the same thing happened... repeated reboot attempts. I shut down the power and turned off the PCIe slot (and GPU) I had been trying and enabled the second PCIe slot and GPU. I turned off the switch on the PSU for much longer than the ten seconds you specified to reset it. When I rebooted absolutely nothing. The MB LEDs are lit but the system doesn't even attempt to boot up.
Please Help!!!