pc power cycling wont boot


pc was working fine when i left but came home and it was just power cycling on and off constantly and won't turn on. I tried disconnecting my gpu. I tried moving the ram to another slot and also tried with just one stick in different slots. I also tried to reset and replace the cmos battery.

when the pc cycles on and off the tiny red cpu light flashes for a split second on the motherboard but not sure what that means if anything. I went to best buy and picked up a corsair RM750e to see if it was the psu and it does the same thing as the one that was in there now so I dont think it is that.

I took off the cpu cooler and cleaned off the thermal paste from the cooler and the cpu and and took out the cpu and put it back in and reapplied thermal paste still nothing

me and a buddy built my pc last year and everything has been working great till now. its like it wants to turn on. the fan spin for a second and it turns off then tries to turn on over and over.

specs that I can remember

i7 cpu 12th gen

deepcool ak620 cpu cooler

asus tuf z690 motherboard

T-FORCE VULCAN Z 16x2 32gb sure about the brand it might be 16gb

seasonic gx 850 psu

evga 3080 ftw3

all the parts were new except for the psu

so far I think I tried everything I can think of not sure what to do other then trying to rma the cpu and mother board they bough were bought at micro center.


  • PowerSpec_MikeW
    PowerSpec_MikeW PowerSpec Engineer
    5 Insightfuls First Anniversary First Comment 5 Awesomes


    Try this. Leave the 24 pin connected, but disconnect the 8 pin CPU power cable. See if the system stays on. It won't POST, but if it stays on, likely indicates the boards VRM is the root cause.

  • Haz
    Haz ✭✭
    Name Dropper 5 Likes First Anniversary First Comment
    Looking at this Issue and your troubleshooting methods. It is highly probable that the motherboard went bad. The good news is that your Motherboard is still within the 3 year warranty that ASUS Provides and you should be able to RMA it without an issue. 

    However the bad news is the ASUS RMA is Slow so expect to wait a couple months for them to send you another motherboard. In the meantime if you would like, you could get another motherboard and then sell the one that ASUS sent back to you at a later date. 

    Sucks that you have to deal with this issue my friend. But sometimes that is how life goes sometimes.

  • db003

    thanks I sent the mother board to ASUS RMA a few days ago will update post if that was the problem

  • Haz
    Haz ✭✭
    Name Dropper 5 Likes First Anniversary First Comment
    Good to know. Let me know if that was the issue. I am hoping the ASUS RMA has improved. 
  • db003
    Name Dropper First Comment
    edited January 13

    I got my motherboard back from ASUS today and reassembled my PC, and it turns out it was in fact the motherboard that was the problem. The paper that they sent with it said the problem was "powers on but no response." If you can call that an answer, that's it.

    It's up and running now, but I had another problem. I had bought a cheap Windows 11 key from scdkeys when I first built my PC last year, and I just found out that it couldn't be used after I switched motherboards since it was an OEM key and that it was from Windows 7. apparently that is what Microsoft told me. I used a workaround, got a license. dont ask lol

  • Haz
    Haz ✭✭
    Name Dropper 5 Likes First Anniversary First Comment
    Yeah I was most likely sure that the motherboard was the issue after you were tried  switching ram modules, clearing cmos, and switching PSU and found that it didn’t work. It sounds like you got your replacement motherboard within 8 days which is not bad. Usually the normal RMA time is about 5-8 days.

    As far as the OEM key goes. You are correct that the OEM key is only good for one motherboard. Once you switch motherboards you will need to purchase another OEM key. That is one of the tradeoffs with OEM keys, on one hand it is dirt cheap at olny around $20, but then it can only be used ounce. 

    With a legitimate key bought form Mircosoft for around $100 the key is good for any motherboard whether you switch them or not.

    you are also correct that there is a workaround for the OEM key for a different motherboard. However I will not say because there are many tutorials out there.

    Im glad you got your motherboard resolved and it sounds like me that ASUS has good RMA service (at least for motherboards). 

    Happy Gaming,

    Haz the IT PRO
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