PC Shuts Down Unexpectedly During Start-Up

tephen04 · 09 Dec 2017

Hello everyone!

I need your help with my PC. It just shuts down itself after between 2-30 seconds everytime I turn it on. There is no BSOD or any beep. This is what I did for the couple of hours:

1. Disconnect all connected loads from PSU except the 24-pin, and the 8-pin for CPU. I run the PC but still shuts down.
2. Disconnect the PSU from the case. Test is using the "paperclip" method; all voltages are within the limits (+/-5% for 5v and 3.3v and +/-10% for 12v). Connect a chassis fan to the PSU then run continuously for a couple of hours. PSU does not shuts down. (I dont have a spare PSU so I cannot replace it to check..)
3. Clean all parts, up to the disassembling the CPU, then reassemble. Still shuts down. (I dont know if CPU itself is OK, i have no way to check it..)
4. Reset the CMOS and replace a new one. Still have problem.
5. Rearrange the RAM modules; use each one (I have 3) for each slot (my MoBo has 4 slots) but still shuts down. I also removed all RAM then run. I expect a beep but it didnt have any single beep when turned on.
6. I disconnect all cables connected to MoBo except the Power SW and SPEAKER, thinking that there is shorting. Still have problem.
7. I put insulations (cardboard) between the mounting bolts and Mobo and between MoBo and the nut under the MoBo (dont know what it is called). Still no luck.
8. I then decided doing something more "risky". I run the PC as usual, and as expected, it shuts down. But I didnt turn off the PSU, instead I removed the 24-pin from the MoBo. Then I wait some 10 seconds and reconnect it to MoBo. The chassis fan which is connected directly to PSU (as I said in 2) thru Molex runs and then shuts down. And then again, I removed the 24-pin without turning off the PSU, and then perform AGAIN the paperclip method (dont worry, I am somewhat "brave" in handling a DC system.) and then check the supply the voltages in each pin and they are all OK. I also noticed that at the time I removed the 24-pin from the MoBo, the chassis fan suddenly runs.

My conclusion as of now is that my MoBo is faulty.. Am I correct? That last test I did was proof that the PSU does not shuts down because of "over or undervoltages" because I think you cannot remove that type of alarm from PSU without turning it off, so I am somewhat convinced (60%) that PSU is not the problem.

Please instruct me on what to do next in order to fix my problem..

Thank you very much, guys!

RoasterMen · 09 Dec 2017

This is the exact problem that I encountered with my system yesterday. CMOS reset did the trick up until I installed all the parts inside the case, it happened again.

I believe it has something to do with the temperature. Have you checked your processor temp? It's probably running over the warning temp the BIOS is set in.

Megahertz07 · 09 Dec 2017

I have the same issue with a Z87 and i5. Computer shutdown. No BSOD - Windows 7 Help Forums. I still don't know if it is a CPU or MB problem.
A friend had same problem and it was the CPU.

tephen04 · 09 Dec 2017

RoasterMen said:

This is the exact problem that I encountered with my system yesterday. CMOS reset did the trick up until I installed all the parts inside the case, it happened again.

I believe it has something to do with the temperature. Have you checked your processor temp? It's probably running over the warning temp the BIOS is set in.

I cannot check the temperature of CPU since it is so sudden (2 seconds).. To check temp, i may need a thermogun which i dont have here. I also didnt install my monitor, it doesnt display anytime at that time. Cant even check the BIOS UEFI. CMOS reset is no good to me though.

EDIT: is it possible to overheat the CPU in just 2 seconds? I touched the exposed copper of my CPU cooler (Deepcool Ice Edge) but i didnt feel any heat from it. I replaced the thermal paste, BTW, after cleaning the whole unit.

RoasterMen · 09 Dec 2017

Nope, it is not possible for any processor to heat up at it's danger point within 2 seconds.

So it seems like it's not a processor problem, it looks like it has something to do with the motherboard being faulty already (but I am not so sure).

tephen04 · 09 Dec 2017

Megahertz07 said:

I have the same issue with a Z87 and i5. Computer shutdown. No BSOD - Windows 7 Help Forums. I still don't know if it is a CPU or MB problem.
A friend had same problem and it was the CPU.

But I hope it is not the motherboard or the CPU.. Dont want to do upgrades..

I need a confirmation from the experts of SF..

tephen04 · 09 Dec 2017

RoasterMen said:

Nope, it is not possible for any processor to heat up at it's danger point within 2 seconds.

So it seems like it's not a processor problem, it looks like it has something to do with the motherboard being faulty already (but I am not so sure).

Then how can you be sure? What specific test do you recommend me to do?

Acova · 09 Dec 2017

I will probably look like an amateur with the post I've prepared just now but anyways, I decided to share my thoughts regarding this thread:

tephen04 said:

It just shuts down itself after between 2-30 seconds everytime I turn it on.

You refer to the time frame: from the moment you push power button till whenever it shuts down. Correct?
If not, I would make an extra test and hold the startup at BIOS phase or whatever there is but to not go beyond the phase of OS loading and let it run for however long it can (obviously, no need to wait for more than 5-10 mins). Such experiment, might reveal extra logic regarding PC's condition.

If it shuts down from the moment you push power button - yes, it could be indeed the motherboard/RAM/CPU/PSU. I've never had a case when the RAM would be the cause, but so it was with MoBo/PSU.

You could inspect MoBo for anything that may look off the standard, maybe some cylinder exploded or got opened, check for those on-card chains/links conditions too, see if you find any crack or cut.

Also, given you used to work with this machine before, your knowledge regarding how the machine used to work before - can help you to determine faulty device too. If your machine used to work all fine whole time but suddenly began shutting down like this, then it rather indicates on MoBo / PSU. If it was CPU, then your machine would run working different periods of time each time, as it heats up through processing stuff - which is not a stable or fixed variable.

I would rely on knowledge about each component of PC alike described above, or at least, in that fashion. Take into account component's age as well. I don't expect your PC being brand new given the mentioned disassembly of CPU.

Emm, another thought is that if you ever managed to start up whole system to the point when OS was loaded, then, maybe some records were made in Event Viewer Logs (don't remember if it can leave some records elsewhere, this is given you run Windows of course) - this would suggest you trying to run OS via other machine if possible, and going through the information it may have managed to record for you on HDD.

You could also attempt to open PSU for inspection. See if its internals are in good/standard condition.

tephen04 said:

RoasterMen said:

Nope, it is not possible for any processor to heat up at it's danger point within 2 seconds.

So it seems like it's not a processor problem, it looks like it has something to do with the motherboard being faulty already (but I am not so sure).

Then how can you be sure? What specific test do you recommend me to do?

Making sure that every other component is not guilty, e.g. if the rest works, what comes to remain is MoBo being faulty.

You wrote that you have no way to check if CPU is faulty, but here you may try to recall if your machine used to work slower than before, before these series of shut downs came to light. Also, have you always been taking care of CPU, e.g. its temperature control, thermal-paste, dust-free condition? If you know that you did take care of it periodically, then perhaps it helps to point out MoBo/PSU.

I hope the information I wrote earlier helps you in any least way it can.
Obviously if you had 2nd alike components to test each one of them - it would take no time to determine what problem PC experiences there, but at times like this one, every observation of work stability of PC before these failures - they may really help you at some point. I believe if you think back about all of it, you will find extra confidence in either of your findings from those experiments made.

Added:

tephen04 said:

But I hope it is not the motherboard or the CPU.. Dont want to do upgrades..

I need a confirmation from the experts of SF..

I am not an expert, telling it beforehand. (though, it's probably visible without me mentioning it)

tephen04 · 09 Dec 2017

Thank you, Acova, for your eagerness to help me (just by looking at your long reply)!

The hard part of my troubleshooting is the part that I dont have access to any unit that i can trial-and-error on so I cant set ky mind easily. I already thinking of buying a cheap LGA1155 MoBo just to try (my MoBo is already phased out so I have no choice). Thinking of how hard to replace MoBo while retaining my old windows makes me feel very bad (i think that is not just as simple as replacing the MoBo and im good to go).

BTW, let me ask you a question regarding your statement about CPU problem; what do you mean by "If it was CPU, then your machine would run working different periods of time each time, as it heats up through processing stuff - which is not a stable or fixed variable."? I noticed my PC to be running slower but I dont think it is so abnormal because I can still run games like GTA V smoothly, or open and use Office or watching streaming videos at the net one at a time or all at the same time. It sometimes happen that when I run a program, lets say Office, it loads slower, but then again, when it opened, I can use it smoothly without delay in my typing or applying edits in the texts.

I will do your first advice tomorrow, it is now midnight here so I cant do it now. I will update you for the result tomorrow.

I also will connect my monitor and HDD during trial, just to know if it loads the windows normally. But it just worries me that I dont hear the single beep when I turned on the PC which I always hear at the time that this PC works.

RoasterMen · 09 Dec 2017

tephen04 said:

Then how can you be sure? What specific test do you recommend me to do?

I am not sure. That problem has many causes.