PC proceeds to POST then shuts down

[Senordelsol]

Hello guys,

When I try to boot in normal condition my pc goes through POST, I get one short O.K. "BIP" but then right before being able to get to the bios everything goes down.



LONG STORY :
My mobo is ~8 months old, my PSU ~5 months old, I built it on my own and never had a single problem for a year except a dead PSU (which I therefore changed).
A couple month ago I went on vacation for a month and left my setup plugged but turned off. When I came back I couldn't get windows to load half the time I would try though I could stay on bios as long as I wanted.
I could sometimes get to my desktop but it would eventually shut down after a couple hours.
It got worse after two days as windows became definitely unreachable.
I took my build to tech guys, they gave it back the day after saying everything was ok "we applied some new thermal paste, yours wasn't properly set, your pc was too hot"
Translation -> we found nothing but we got a pretext to charge you something and not look like fools.
But oops, turns out I never ever have had a temp issue, and for some reason I had the OCD to check if the temp was okay every 10min for a whole year. Aaaaand I found later that they applied it like shit.
Anyway I took it back home, tried to boot, pc shuts down before getting to bios.
-> once again back to tech, they take me with them into their lab to illustrate that they take me seriously and manage to keep my build overnight to test each composants (yea, finally).
Results : according to them RAM is good, GPU good, CPU good. Now, when they tried a new PSU they got a runtime of 15 hours before a crash. They concluded it was my mobo.
I RMAd my mobo (3 weeks of waiting) and got it today.
I press the "direct bios" button (I no longer bother to try getting windows) -> uptime of 6 sec.

Great. I strip the mobo of everything only to try booting with MOBO-CPU-VENTIRAD-PSU.
Result : runs flawlessly. I have to turn it off manually. Bips telling me RAM is missing.
I try adding 1 RAM : bips saying VGA is missing, shuts down after some sec. Same outcome with my other RAM.
I add my GPU : bip "everything is fine", shuts down after some sec.



SHORT STORY :
regular build : shuts down after 6 sec, bips "O.K."

booting without RAM, SATA, GPU and so on: runs seemingly endlessly, I have to shut it down manually, bip stating missing RAM.

booting with 1 RAM : shuts down after 6 sec, bip stating no VGA detected.

All fans are working, nothing worth noting except they spin VERY fast because I cleared CMOS and thus reseted all fans settings (max is default").

I consider testing once again, and for all, my PSU and my RAM, but other than that I'm lost.


SPEC :
Sabertooth 990FX R2.0
FX8350 Black Edition
EVGA supernova 750w
Corsair Vengeance 2x4
1x SSD, 1x HDD


If anyone has some tips or insights to share, I'm all ear.
What would you do?
What did I miss?
Please feel free to contribute!

PS: apologies if my grammar sucks, I am french.


UPDATE, SOLUTION :
PSU passed out, tech guys missed it twice. 2 months lost.

 

[Brandon-]

Hello guys,

When I try to boot in normal condition my pc goes through POST, I get one short O.K. "BIP" but then right before being able to get to the bios everything goes down.



LONG STORY :
My mobo is ~8 months old, my PSU ~5 months old, I built it on my own and never had a single problem for a year except a dead PSU (which I therefore changed).
A couple month ago I went on vacation for a month and left my setup plugged but turned off. When I came back I couldn't get windows to load half the time I would try though I could stay on bios as long as I wanted.
I could sometimes get to my desktop but it would eventually shut down after a couple hours.
It got worse after two days as windows became definitely unreachable.
I took my build to tech guys, they gave it back the day after saying everything was ok "we applied some new thermal paste, yours wasn't properly set, your pc was too hot"
Translation -> we found nothing but we got a pretext to charge you something and not look like fools.
But oops, turns out I never ever have had a temp issue, and for some reason I had the OCD to check if the temp was okay every 10min for a whole year. Aaaaand I found later that they applied it like shit.
Anyway I took it back home, tried to boot, pc shuts down before getting to bios.
-> once again back to tech, they take me with them into their lab to illustrate that they take me seriously and manage to keep my build overnight to test each composants (yea, finally).
Results : according to them RAM is good, GPU good, CPU good. Now, when they tried a new PSU they got a runtime of 15 hours before a crash. They concluded it was my mobo.
I RMAd my mobo (3 weeks of waiting) and got it today.
I press the "direct bios" button (I no longer bother to try getting windows) -> uptime of 6 sec.

Great. I strip the mobo of everything only to try booting with MOBO-CPU-VENTIRAD-PSU.
Result : runs flawlessly. I have to turn it off manually. Bips telling me RAM is missing.
I try adding 1 RAM : bips saying VGA is missing, shuts down after some sec. Same outcome with my other RAM.
I add my GPU : bip "everything is fine", shuts down after some sec.



SHORT STORY :
regular build : shuts down after 6 sec, bips "O.K."

booting without RAM, SATA, GPU and so on: runs seemingly endlessly, I have to shut it down manually, bip stating missing RAM.

booting with 1 RAM : shuts down after 6 sec, bip stating no VGA detected.

All fans are working, nothing worth noting except they run VERY fast because I cleared CMOS and thus reseted all fans settings (max is default").

I consider testing once again, and for all, my PSU and my RAM, but other than that I'm lost.


SPEC :
Sabertooth 990FX R2.0
FX8350 Black Edition
EVGA supernova 750w
Corsair Vengeance 2x4
1x SSD, 1x HDD


If anyone has some tips or insights to share, I'm all ear.
What would you do?
What did I miss?
Please feel free to contribute!

PS: apologies if my grammar sucks, I am french.

Hi senordesol,

If the issue doesn’t persist in Safe mode, then the issue might have caused due to some software on your computer.



Step 1: Perform a clean boot

Visit the link below to know how to perform a clean boot.



http://support.microsoft.com/kb/310353

Note: Once the troubleshooting is over, reset the computer to start as usual.

 

[Senordelsol]

I can't clean boot.
My pc shuts down whether the SSD is plugged or not.
In fact, the only context in which it doesn't shut down is when there is only my cpu.
But as soon as I add RAM it shuts down after 6 sec or so.

 

[elmie]

since you've taking everything out or tried booted with very very limited add-ons to the booting process. like just with 1 stick of ram, not HDD and video card plugged in. and still nothing, I would take the CPU out and look at the socket with a torch., yes that's right, anything can happen. surprisingly this happens a lot with backyard computer tech. accident do happen despite how many years you have done this b4.

 

[St00pid]

Great. I strip the mobo of everything only to try booting with MOBO-CPU-VENTIRAD-PSU.
Result : runs flawlessly. I have to turn it off manually. Bips telling me RAM is missing.
I try adding 1 RAM : bips saying VGA is missing, shuts down after some sec. Same outcome with my other RAM.
I add my GPU : bip "everything is fine", shuts down after some sec."

Seems like your motherboard is working just fine.
This behavior can indicate insufficient PSU power. It could be that your PSU is defective and does not output the wattage it should.
Do you have another psu that you can try or a low-end graphics card?

 

[Senordelsol]

I went back to those tech guys today, only to give them the PSU alone, to make sure they have no other choice but to plug it on a sane computer and not the other way around.
Turns out the PSU is dead just as I suspected from day 1. They had it in their hands 3 times in 2 month yet I had to make sure to tell them exactly what to do to get some reliable results.
Lost 1 month of waiting my mobo in RMA, which by the way came back "fixed" according to the paper attached with it. Makes me wonder.


That was actually the only outcome that made sense. Everything always worked like a charm, I leave my computer unintended 1 month and nothing is the same. I mean it doesn't break by itself. Was it thunder?
Maybe I should get protection.
I'll try to RMA it and see if nothing else got burnt.

I'll edit my 1st post to make the solution more visible, and I'll keep updating.
Thank you guys!