Ot: PC Not starting up (help)

VMP wrote on 9/14/2015, 1:18 PM
This really is a strange issue.

Suddenly our second PC doesn't respond to the start button (this already happened a week ago).
The Motherboard green led is on.

I have:
- Connected another power supply, still doesn't start.(The donor power supply did have another 4 pin 12v MOBO top left connection but that shouldn't be a problem)
- Checked If the button is broken (when pressed the Power supply gives another high pitched tone than when idle. Also manually connected the pins together with metal)
- Checked the little motherboard battery, have replaced it, still doesn't start, then put the original back on it.
- Started the pc without connecting anything on it.
- Removed the graphics card and tried it.
- Changed the power cord.

The most strange thing about it is when I brought it back to the pc dealer, it just started again!
So they could not find anything strange about it. But I knew that not finding any problem would make it return.

Now some days later... the same issue.

The only thing that could be different at the dealer is their power grid, I presume, So I went and tested the pc at the neighbors house but still the same.

The night before this occurred for the first time there was a lighting strike not too far away.
But all the other PC's are fine. So that may not be the issue.
I have build Pc's before so I am not a total noob.

What do you guys think?

Motherboard: P8H67-M LX
OS: Windows 7

PC hardware info:

Intel Core i5 2500 @ 3.30GHz 33 °C
Sandy Bridge 32nm Technology

4,00GB Dual-Channel DDR3 @ 665MHz (9-9-9-24)

ASUSTeK Computer INC. P8H67-M LX (LGA1155) 30 °C

1024MB ATI Radeon HD 5400 Series (ATI AIB) 40 °C

238GB Samsung SSD 840 PRO Series ATA Device (SSD) 29 °C
931GB Western Digital WDC WD10EALX-009BA0 ATA Device (SATA) 33 °C


1. Changed the power supply.

2. The 12V ATX on the corner of the MOBO is connected, the PC ran fine with the new PSU, it's the next day that it fails to power up again (until it stands for 24-48 hours without power, then it starts and runs, untill it fails to start the next day...the cycle goes on)

3. I have connected the PWR SWTCH pins manually to jump start it, the same, so its is not the power button either.

Like another member mentioned: Some of the capacitors of the motherboard might have been depleted.

The PC is now at the dealer.

I'll keep you updated.



musicvid10 wrote on 9/14/2015, 2:04 PM
Did it beep when you pushed the start button?
No beep = no talky to CPU.
OldSmoke wrote on 9/14/2015, 2:17 PM
Check Power Supply and CMOS Battery.

Proud owner of Sony Vegas Pro 7, 8, 9, 10, 11, 12 & 13 and now Magix VP15&16.

System Spec.:
Motherboard: ASUS X299 Prime-A

Ram: G.Skill 4x8GB DDR4 2666 XMP

CPU: i7-9800x @ 4.6GHz (custom water cooling system)
GPU: 1x AMD Vega Pro Frontier Edition (water cooled)
Hard drives: System Samsung 970Pro NVME, AV-Projects 1TB (4x Intel P7600 512GB VROC), 4x 2.5" Hotswap bays, 1x 3.5" Hotswap Bay, 1x LG BluRay Burner

PSU: Corsair 1200W
Monitor: 2x Dell Ultrasharp U2713HM (2560x1440)

VMP wrote on 9/14/2015, 2:26 PM

Nothing at all, even the fans don't turn, ony thing is the green led which is always on, on the Mob.


I have checked both as mentioned above :-)

But like musicvid maybe it is the CPU, going to take out the CPU and put it back again, maybe there is a loose connection.

Does a Motherboard start without a CPU? Or atleast doe the fans turn? Just to make sure if it is the CPU.

astar wrote on 9/14/2015, 3:34 PM
Since it worked at the dealer, have you tried a new power cable to the power supply? tried the unit in a different outlet in the house?

Have you verified the ground and power leads to the outlet you run the PC from? Is the outlet a tight fit or looser than a ...well you get the idea.

A killa-watt or checking the UPS status would verify good power voltages and ground.

If you replaced the PSU and it fires up at the dealer, it leads me to suspect the power at your location.

If not this, then reseating CPU, memory, and pulling out any add-on cards and USB devices not needed, so the MB is just GPU. Motherboards will not start with out CPU, but most will give beep codes to indicate no CPU, Memory, or bad CMOS battery.
DavidMcKnight wrote on 9/14/2015, 4:14 PM
Not that this helps you directly, but it may seem far-fetched to suspect local power. It isn't. Is there anything else on the circuit? Try a different circuit in that building.

Wife's PC was humming along for months. Added a brand new laser printer to her office. As soon as the printer fired up, her PC shut down.
Bliss Video Productions wrote on 9/14/2015, 5:24 PM
Just for grins, try this...

Unplug the power cable either from the back of the PC or from the wall -- preferably from the back of the PC.

Then press and hold the power button for a few seconds. This discharges any built-up current in the circuitry.

Re-attach the power cord and see if it will turn on. This has actually cured a thing or two for me in the past.

It's definitely conceivable that your power cord is bad. Rare, but it does happen. When you took it to the dealer, did they use your power cord or a cord of their own?

Did they also use your keyboard, your mouse, and your monitor? If not, one of these things could be causing a problem. Try disconnecting all three and see if the PC powers up. Disconnect anything else you have attached as well, like speakers, external drives, network cables, etc.

Does your PC connect directly to the AC outlet in the wall? Or does it go through a power strip, extension cord or UPS first?
Bliss Video Productions wrote on 9/14/2015, 5:29 PM
And I still wouldn't rule out a flaky power supply. The fact that the other power supply you tried it with had an extra power connector hints that it may not necessarily be compatible with your motherboard. All supplies are not created equal.

If you've taken out ALL of the cards (not just the graphics card) and disconnected EVERYTHING so it's just the CPU connected to the wall with a power cable, and it still won't boot then most likely it's the power supply. I can't think of anything on a motherboard that would stop working, then start again, then stop again. Flaky power supplies can cause some very odd symptoms.
GeeBax wrote on 9/14/2015, 5:52 PM
You can forget anything to do with the AC power, because if there is an LED lit up on the motherboard, then there is supply.

The most likely problem is the power supply. Failure of the power-on circuit is quite common in PCs.

The 4 Pin connector from the other supply is most likely the additional power feed provided for a GPU, and should not affect whether it switches on or not.

It is also possible there is a shorted capacitor on the motherboard that is stopping it from powering up as well, but this is not as easy to find and remedy.

PeterDuke wrote on 9/14/2015, 7:08 PM
Don't forget to check that the cable from the start button to the motherboard has not become unseated.
TheHappyFriar wrote on 9/14/2015, 7:51 PM
Don't forget to check that the cable from the start button to the motherboard has not become unseated.

That's why my new rig didn't turn on. PSU connection to MB came loose when I put the cover back on the case.
VMP wrote on 9/15/2015, 9:38 AM
Thanks for the feedback guys.

The good news:
I let is stand for a day without power. It now starts.....

The strange thing:
It first started to run 3 seconds then shut off, then again, the third time it kept running.

Like kickstarting a combustion engine so to speak.

Now I remember that also at the dealer it stood there for a day or two before they powered it up so that might be the reason it started there too.

I still dont know the exact reason.
I think this is some kind of a strange memory issue. Or a loose hardware connection.

I have now swapped out the CMOS battery for a new one, the bios resetted and I have set the date etc. Hope that helps.

So let us hope it now keeps running and starting.

To anwser some of your questions:
- The start button and the connection to the mobo is fine.
I have even manually connected the button pins together on the mobo to start it manually, as stated in my first post.
- I havent checked the power grid with watt meter etc, but there are three other similar PC's running fine. (Also alternatively) so the power grid should not be the problem.

If I knew which part of the PC is faulty then I would replace that immediatly. But for kow it still is an Enigma, if it keeps running fine then I'll be happy.

I'll keep you updated.

The power supply is CX 500 from Corsair: http://www.corsair.com/en-us/cx500-80-plus-bronze-certified-power-supply

Do you consider this to be underpowered? Then I could anyway swap the power supply aith another just to be sure.

This PC we use for the pre production, no heavy Vegas editing going on here, but still it is as important, and due to the SSD it is very fast!


Now that it is running I ran Speccy and this is the PC hardware info:

VMP wrote on 9/15/2015, 1:38 PM
Just an Update:

I have bought the Corsair VS550 power supply.

The high pitch sound of the original power supply could be caused by depleted capacitors.

Lets see if this is the solution.

I have also changed the CMOS battery.

VMP wrote on 9/16/2015, 9:41 PM
Well guys.

It's not the Power supply.

I have changed the power supply, it ran for a day...since this morning it doesen't start.
Green light is on. Also changed the CMOS battery.

So, maybe it's the motherboard, the cpu...ram?

The thing is that if I knew which it is, then I would spend another 100$ and be done with it.
But If I end up replacing them (in the wrong order) all with the same make/model then I rather replace them with the latest (faster system).

I think I am going to bring it to the PC dealer, but maybe when it is there the PC might start again, and they wouldn't understand the problem.

I have made a detailed log list, of what happened when, I am going to give that too.
It seems to me that when the power is out off the PC for some days, the problem goes away for a short while.

I'll keep you updated.

TheHappyFriar wrote on 9/17/2015, 5:55 AM
Power supply connector testers are pretty cheap and avoid thinking "Hey, it could be the PSU/power to stuff". Volt meters would actually test the switches.

I highly doubt it is the CPU/RAM/GPU. Most motherboards make distinct beeps when those don't work. It could very well be the MB, or both MB+PSU. My P3-667 MB+PSU went at the same time once. A storm messed up the PSU, which messed up the MB, which when I replaced one at one time messed up the other. The green light just means that green light gets power. It would be like a single lightbulb in your house being turned on and saying "The house has power!" even though nothing else works.

If the PSU can be confirmed working (via PSU tester), the switches can be confirmed working (via volt meter), the power cord can be confirmed working (via volt meter), the socket is working good (via socket tester & volt meter), then to rule out the CPU/RAM you'd need to test those in another machine. If you can't then you'd have to assume it's the CPU/RAM (which is unlikely unless there's a beep from the MB) or MB.

You DO have the speaker connections to the MB so you can hear the beeps?
musicvid10 wrote on 9/17/2015, 7:29 AM
Try a different CPU is a good place to start.
Go to a used computer store; they should be glad to help.
I wouldn't go buying stuff to test a dead computer.
Bliss Video Productions wrote on 9/17/2015, 8:25 AM
TheHappyFriar reminded me of an issue I encountered way back when I did field hardware support. It occurred with a particular brand of computer -- can't remember which one now, but I don't think they're around anymore. Whenever there was a thunderstorm, afterwards we would get a lot of calls from people who owned this brand of computer, saying it wouldn't boot up.

We discovered the problem was the modem card. If we removed the modem card, the PC booted right up. So we simply replaced that card.

So again, I would take out EVERY card and any other device attached to the motherboard or the PC itself -- drives, monitor, keyboard, mouse, external drives, card reader, USB devices, etc. -- so you're basically left with motherboard, CPU, memory and power supply. Then power it up. Granted, the PC may not 'boot' in the real sense, but if it reacts as though it has power -- fans spin up, etc. -- then that indicates that something connected to the motherboard is causing the problem. In which case you can re-add devices, one by one, until you find what the problem is. (The first thing I would re-add is the graphics card, if there is one, then attach a monitor so, if the problem isn't in the graphics, then you may see some error message on the screen which may help.)

If, with everything disconnected, it still doesn't respond to your attempt to power it up, then it's going to be either the power supply, the motherboard, the CPU or the memory -- or perhaps a combination of 2 or more of those things.

Remember to ALWAYS use a static grounding strap when working inside your PC. You'd be amazed how many problems that will prevent.
VMP wrote on 9/17/2015, 1:55 PM
Thanks for the feedback guys, much appreciated.

I did take out all the cards and everything connected still the same.

@ Bliss Video Productions

Ethernet (modem) is build in the MOBO, the only separate cards are: Graphics and USB 3 expansion card containing 2 extra USB 3 ports.

@ TheHappyFriar

Good one, the speaker was indeed not connected, but nothing starts, so there is no beep.
Equal to PC starting without the power cord plugged in, except the Green Led is on.

Power Supply has been replaced and is New (bought it yesterday), Power Cord is Fine, Power Button is Fine. Also changed the CMOS battery.

@ musicvid10
Thanks for the tip.

I have brought the PC to the dealer and asked them to press the button, this time also at the dealer it didn't start. In this case that's a good thing and they could see something IS wrong with the system.

I'll let them sort it out now.

I have made a log of the problem.

In short
- A. PC doesn't start (power up).
- B. When the PC stands for 1-2 days without power, it starts. After it powers up it runs for some days.
- C. After it is turned off, the next day it doesn't start.

Then we get back to A. 1-2 days without power, it starts.

This is something we all can learn from.
Untill now it is still an Enigma.

I'll keep you updated.

craftech wrote on 9/17/2015, 6:51 PM
Two thoughts:

1. Does it have a 12v ATX connector and was it plugged in?

2. Have you jumpered the start switch on the case or jumpered the motherboard start pins?

VMP wrote on 9/17/2015, 7:13 PM

1. Yes the 12V ATX on the corner of the MOBO is connected, the PC ran fine with the new PSU, it's the next day that it fails to power up again (until it stands for 24-48 hours without power, then it starts and runs, untill it fails to start the next day...the cycle goes on)

2. Yes I have connected the PWR SWTCH pins manually to jump start it, the same, so its is not the power button either.

Like another member mentioned: Some of the capacitors of the motherboard might have been depleted.

The PC is now at the dealer.

I'll keep you updated.


PixelStuff wrote on 9/19/2015, 2:11 AM
Generally if your fans don't turn on, it will be either the Power Supply or the Motherboard. You said you replaced the power supply and it still happens so that leaves the motherboard.

My secondary speculation is that if unplugging it for a few hours always restores functionality, then you probably have a bad capacitor somewhere on the motherboard.

I would not expect the CPU, RAM, or GPU to prevent the fans from spinning.
craftech wrote on 9/19/2015, 10:28 AM
Out of curiosity I looked up the user reviews at Newegg for that motherboard. Read a few of them.

VMP wrote on 9/19/2015, 12:20 PM

That is what I am hoping it is, then it wouldn't be an expensive fix, just replace the original motherboard (around 100$), and not the total system (500$ +).
The dealer has a third party dealer which can still deliver unused past models.

I have phoned the PC dealer, due to many other clients, It will take a while before they can check the PC and motherboard.
I have told them that it could be the capacitors on the MOBO and that they shouldn't wait too long before they do the diagnose, or it will start again due to it being without power. They said that it doesn't matter for the diagnose if it powers up or not. So let us see.

The thing is that the PC (when it boots up) runs great, and as fast as my i7 Vegas editing system (generally). So spending hundreds $ more for a total new system is just overkill, for what we do with it (basic pre production stuff).

I have upgraded it with the expensive Samsung SSD Pro so it runs and boots up Really Fast, and stays to do so since its upgrade.

craftech, John,
Hmm.. those are indeed a lot of complaints.

At the time we bought that PC as a set, for a reasonable price.
I guess that means that you can expect these kind of mediocre components in it.

That is the reason that I build my editing PC's myself, and choose the components after a good research.
Like ask you guys first before purchase: http://www.sonycreativesoftware.com/forums/showmessage.asp?Forum=4&messageid=859640

John222 wrote on 9/19/2015, 1:28 PM
You can get a recertified mb for $40 at Newegg.

VMP wrote on 9/19/2015, 2:46 PM
I didn't get any result John, Search Term: "P8H67-M LX"


Also I am situated in the Netherlands, Europe, so the transport cost may make it much more expensive I think? I can't find how much they charge.