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Resolved Question

Help Identifying Hardware Issue

Jan 2, 2015 12:42AM PST

Yesterday my PC restarted itself without warning. After logging back on, I had approximately five minutes before this repeated. The second time I logged back on, it didn't restart again but blackscreened. My immediate reaction was yo turn it off by the power button but I was unable to. Now whenever I turn on my PC, I'm unable to even boot but the power of all fans and hardware seem to be active.

Hardware:
M5A78L-M/USB3 (if I read that off the board correctly)
Cooler Master GX 750W Bronze PSU
AMD 8320 Black Edition CPU
EVGA GeForce 660ti FTW Signature 2 GPU
OCZ Vertex 4 as my main
WD Black as my secondary
Cooler Master Storm case, cant remember which model but nVidia edition.

Tried Methods:
CMOS reseat
Hardware clean
Reinstall RAM to diff slots
Different PSU cable
Output from both GPU and Motherboard built in graphics

All methods yield the same power on, unable to turn off unless switching off the PSU and no booting up. If anyone could help with ideas as I'm not even close to tech savvy, I'd appreciate it. Thank you.

Discussion is locked

PseudoScopic has chosen the best answer to their question. View answer
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Clarification Request
Just in case you didn't know.
Jan 2, 2015 12:48AM PST

There's another power button push some newer folk don't know. IT MATTERS HERE!

Hold the power button for 4 to 15 seconds to force power off. If that fails it's the PSU or motherboard.
Bob

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Clarification
Jan 2, 2015 2:47AM PST

It definitely does not turn off unless I go straight to the PSU. I removed an optical drive I had which was unlisted and it made a difference. It began to boot, offered me to start windows normally or try and fix the problem so I selected to restore my PC just in case software had any input to the problems. Needless to say it blackscreened during the process. Definitely not a GPU problem considering this test was on integrated graphics. With another post stating it might be my CPU, this is why I am conflicted in what to replace. Thank you for such a speedy response

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That's a bad sign.
Jan 2, 2015 2:57AM PST

If the long power button press fails it points to PSU or motherboard faults. There was this rare board (1 in over a decade) that a new CMOS battery fixed it but I never saw that in over a decade so my bet is there was something wrong with the motherboard.

http://www.coolermaster.com/powersupply/gx-series/gx-750w/ is a single rail +12V and more than ample for the task so it's very low on my suspect list.

There is a slim possibility it's the motherboard mounting. I've lose track of how many times I found extra mounting posts in the case shorting out the backside.

--> The failure to power down with the long button press is damming. That is, IMO that's a board issue 99% of the time. It could be the PWR ON is on the wrong connection but you can check that out.
Bob

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logic circuit
Jan 2, 2015 11:48PM PST
If the long power button press fails it points to PSU or motherboard faults.

that logic signal, just like the Reset function, goes first through the motherboard and cpu, which then sends onward to the PSU.
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I use that without a CPU.
Jan 3, 2015 1:18AM PST

It appears that no CPU is needed for this to work. We have test boards at the office to use as dummy loads for PSU tests.
Bob

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you've had the power off
Jan 5, 2015 3:00AM PST

circuit to work without a CPU on a motherboard?

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Yup.
Jan 5, 2015 3:03AM PST

Remember these are boards that didn't work for other reasons. Such as a broken DIMM slot, blown other ports but useful to power up/down a PSU. The GREEN WIRE TEST is OK but we want to have a small load when check voltages and need a shop board that we don't care if it burns out.
Bob

Best Answer

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Motherboard Problem
Jan 5, 2015 3:23AM PST

This issue was solved by replacing my motherboard, as it was then able to maintain power while roaming the BIOS on screen and the power button functioned perfectly. Another problem presented itself afterwards, not allowing me to boot windows but this was quickly identified as communication trouble between the new motherboard and old operating system installed. This was then resolved with a simple reinstall. Thank you to all those that helped in this forum.

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Answer
sounds like cpu problem
Jan 2, 2015 1:08AM PST

You can grab this to test if motherboard or CPU problem. It will work on that motherboard for testing and emergency use, and less expensive than a trip to a shop.

New, last one.
http://www.amazon.com/AMD-Sempron-145-Processor-SDX145HBGMBOX/dp/B0040BPHJO

I run that Sempron 145 on my Linux box, surprisingly good for a single core, but value for you is a cheap CPU for testing purposes on AM3 and AM3+ motherboards.

I've bought used ones and not gotten a bad one yet.

http://www.amazon.com/gp/offer-listing/B00DMLPL9Y/ref=dp_olp_used?ie=UTF8&condition=used

30 customer reviews
http://www.amazon.com/AMD-Sempron-Socket-Cache-SDX140HBGQBOX/dp/B002I25RWO/ref=sr_1_8?ie=UTF8&qid=1420217877&sr=8-8&keywords=sempron+am3

900+ sold, some remain, S&H= $35 New
http://www.ebay.com/itm/AMD-Sempron-Processor-145-2-8Ghz-1MB-AM3-Retail-Package-/200655277064

I keep several in store box with their HSF for testing AMD motherboards.

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thank you
Jan 2, 2015 2:50AM PST

This certainly gives me some direction to go on but I am still conflicted on what to replace. I know these parts will likely be necessary in establishing the problem but I don't have the money to buy them as testers and then buy something better if I identify the problem. Are there any other tests I could conduct to narrow it down? People are saying it could be the PSU, motherboard and this is the first I've heard the CPU being suggested as the cause. It would be rather costly to go for all three I think

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the average computer user
Jan 2, 2015 11:37PM PST

can measure voltage output from a PSU, but that can be misleading, because it doesn't measure the "draw" or wattage ability before breakdown (when it hits the protective shutdown due to too much power drawn). One thing the user can do is add up the wattage draw at idle of all parts (motherboard, HDD, optical drive, added cards like video, USB devices attached, unpowered speakers, and so on) and compare that to the "continual power" for a PSU instead of the "max power". PSU should all be rated on continual power supply, but many label themselves after their max power, which is how much it can take just before cutting out.

So, what choices are available? Removing everything from the power which can be to achieve the lowest power use toward the bootup of the OS. One of the easiest to lower power requirement is pulling the video card and using a low power card or lower power onboard video for the test. If the system works at low power use, and then doesn't at higher power, then the PSU is insufficient.

What if nothing seems to fully work correctly. Can fans run while nothing else works? Sure can, especially in a dual 12V rail in PSU.

So, what can be done? At that point it's usually either a PSU or a CPU problem, there's not much else connected which could be causing it. You have the motherboard, the PSU, the CPU, a stick of RAM, either HDD or a bootable USB flashdrive.

If you use a good test CPU, and no change, then the problem is one of the other items. The HDD can be tested by unplugging it's power and attempting a boot either by CD/DVD drive, or bootable flashdrive (preferred).

RAM is tested by swapping in one stick, then exchange for the other, rarely both go bad at the same time.

For average home computer "fixer" the three items most difficult to be sure OK or a problem is the PSU and CPU. That ends up at having a known good CPU to test both CPU and PSU. If the test CPU then won't work and all those other moves were made, you are left with the PSU and something internal to the motherboard.

The biggest problems in past with motherboards were blown capacitors easily seen, jumpers set incorrectly on RAM and CPU circuits. In newest motherboards of today, I've not seen jumper or dip switch settings, most anything like that done in the BIOS now, and thankfully the years of "capacitor plague" is falling further behind us year by year.