PC turns on for a second then turns off and repeats

[BlckEagle89]

This weekend my PC entered some kind of cycle where everytime it turns on after a second it turns off, and after 2 or 3 sec it turns on again for a sec and turn off, so Turn On (1 sec) -> Turns Off (3 sec) -> Turn On (1 sec) -> repeat
My rig is this:
Mother: Asus Z97-A
CPU: Intel Core i5 4690K @ 3.50GHz
Powersupply: 750w (Don't remember the exact brand, i will give you this later when i get back home)
Those 3 remains the same since the last 2 years i believe, and recently i bought (thanks to the help of some fellow steam users that gave me good advices)
Video: Sapphire AMD RX480 Nitro+ 8 GB GDDR5
HDD: 1 x Samsung 850 EVO (SSD) + 1 x WB HDD 1TB (this one have like 3 or 4 years and i am using it only for data)
RAM: G.Skill Ripjaws 8GB DDR3 PC3-12800 DC Kit (2x4GB)
I made the usual disconnect everything from the power supply until it was only the CPU connector and the motherboard connected, and it did the same until i disconnected the CPU connector, so only with the motherboard connected to the power supply my rig turned on and remained on. Of course i couldn't see anything because there was no video.
Just to make another test i took a power supply from my work and connected only the CPU and the motherborad to it and the issue was the same, until i disconnected the CPU connector.
Short vesion, i believe there is a problem in the CPU (if it is connected to the power supply it enters this loop), but i can't think on another test to make sure because i don't like the idea of buying a new CPU and then finding that the problem was in another component. Is there another test? How can i make a test in order to be sure that the problem is in the CPU and not the motherboard?
Finally, what do you recommend me (in case the CPU is the broken part)? Change only the CPU or change both CPU and motherboard? Which CPU should i buy next? i5 or jump to an i7?

[Bad 💀 Motha]

Reset CMOS
Then press the "MemOK!" button on the Motherboard.
Enter BIOS, enable XMP for your RAM to ensure it is properly configured.
Double check Time+Date and Boot Options Order; Save & Exit

[BlckEagle89]

引用自 Bad_Motha：

Reset CMOS
Then press the "MemOK!" button on the Motherboard.
Enter BIOS, enable XMP for your RAM to ensure it is properly configured.
Double check Time+Date and Boot Options Order; Save & Exit

Do i press the reset "MemOK!" with the PC on or off?? I assume that i have to move to this step if the CMOS reset was sucessfull and i can turn the PC on and it remains on

[Bad 💀 Motha]

Power Off, Reset the CMOS, then press the MemOK button

[BlckEagle89]

k, will try that today and come back tomorrow with the result

[BlckEagle89]

引用自 Bad_Motha：

Power Off, Reset the CMOS, then press the MemOK button

Tried this but the issue remains. First i resetted the CMOS, then i tried to turn the mother on with the MemOK button but i didn't turn on. I turned on with the power button and it did the same.
Just in case i made a bridge (green + black) in the motherboard connector in order to turn on the PC only connecting the CPU connector (P2 and P3 i believe) and the power supply remained on so there is no issue there it seems. Maybe there is an issue with the power phases of the motherboard? Also, when i disconnect the power cable the motherboard tries another turn on, like if there was still power on it, even if there is no connection to the tension of my house. And everytime the PC turns on again i heard a sound of a switch, something like a relay changing state

[chiefputsa☒lag]

remove gpu and turn on pc.

if problem disappears, you have a failing/poor psu.
if problem persists, test memory stick one at a time and use spare quailty psu (seasonic, silverstone, etc)

[BlckEagle89]

引用自 chiefputsa☒lag：

remove gpu and turn on pc.

if problem disappears, you have a failing/poor psu.
if problem persists, test memory stick one at a time and use spare quailty psu (seasonic, silverstone, etc)

Forgot to mention i already did those two tests, removing the GPU the problem remains, removing the memory sticks one at a time yields no result

[🦜Cloud Boy🦜]

it's your Motherboard's problem. Funny thing is i faced the same problem with my system just 1 month ago. The exact same issue. And after changing my MoBo, everything is fine now.

[BlckEagle89]

引用自 Cloud Boy：

it's your Motherboard's problem. Funny thing is i faced the same problem with my system just 1 month ago. The exact same issue. And after changing my MoBo, everything is fine now.

I was thinking the same, any advice in changing the CPU to a new mobo? Everytime i changed a motherboard i tried to keep the CPU on the mother because i know that CPUs can be very fragile if not handle with care.
After removing the mother, what did you do to change the CPU from one to the other?

[SoldierScar]

I believe it's a PSU issue, i had exactly the same thing. The PSU was 5 months old, i started the pc and after like 5 minutes it started the restart loop. It turned off, turned back on after 2-3 secs but immediately turned off after like 1 second and again and again..i returned it, they sent me a new one and it's working so far like 3 months without a single issue, i hope this one lasts longer :d

[🦜Cloud Boy🦜]

引用自 𝓢𝒐𝒍𝓭𝓲𝓮𝒓𝓢𝒄𝓪𝓻：

I believe it's a PSU issue, i had exactly the same thing. The PSU was 5 months old, i started the pc and after like 5 minutes it started the restart loop. It turned off, turned back on after 2-3 secs but immediately turned off after like 1 second and again and again..i returned it, they sent me a new one and it's working so far like 3 months without a single issue, i hope this one lasts longer :d

that's not exactly the same. his system did not last 5 minutes, it does not even boot up. it's a 2-3 seconds loop cycle. NOT 5 minutes.

[🦜Cloud Boy🦜]

引用自 BlckEagle89：

引用自 Cloud Boy：

it's your Motherboard's problem. Funny thing is i faced the same problem with my system just 1 month ago. The exact same issue. And after changing my MoBo, everything is fine now.

I was thinking the same, any advice in changing the CPU to a new mobo? Everytime i changed a motherboard i tried to keep the CPU on the mother because i know that CPUs can be very fragile if not handle with care.
After removing the mother, what did you do to change the CPU from one to the other?

CPUs are not that fragile. Unbox and prepare your new MoBo before removing the CPU from the old MoBo, after removing it from the old MoBo, just put it directly in to New MoBo instantly. No need to put it anywhere else. You can apply some new thermal paste if you want. Not that Hard.

[BlckEagle89]

引用自 Cloud Boy：

引用自 BlckEagle89：

I was thinking the same, any advice in changing the CPU to a new mobo? Everytime i changed a motherboard i tried to keep the CPU on the mother because i know that CPUs can be very fragile if not handle with care.
After removing the mother, what did you do to change the CPU from one to the other?

CPUs are not that fragile. Unbox and prepare your new MoBo before removing the CPU from the old MoBo, after removing it from the old MoBo, just put it directly in to New MoBo instantly. No need to put it anywhere else. You can apply some new thermal paste if you want. Not that Hard.

I will have to start looking for a new mobo then, what do you guys recommend me? Which mobo should i get? I think the one that i have is no longer in stock

[Ashlek]

Before you start looking for a new motherboard, try removing one of your RAM sticks and try powering your pc on. If the issue still persists, swap the RAM stick for the other one. It may just be a faulty RAM stick causing your PC to boot loop.

[BlckEagle89]

引用自 x-$had0w：

Before you start looking for a new motherboard, try removing one of your RAM sticks and try powering your pc on. If the issue still persists, swap the RAM stick for the other one. It may just be a faulty RAM stick causing your PC to boot loop.

Will try that again today when i get back home