PC (new build) power cycles around 5-6 times then works OK (ish)- Frustrating problem -SOLVED

[archerboy]

My son and I recently built a fairly high end gaming machine, our 5th build over the last few years. This time we are having an issue that we have never had previously. When the machine is turned off completely, i.e. overnight disconnected from power source, it power cycles between 5-6 times then boots up OK when powered up in the morning. The motherboard shows code A0 after bootup. The GPU has two flashing red led's that stay on all the time (including when the  PC is powered down but still connected to power.

After it goes through this power cycling the PC seems to function normally other than the GPU flashing led lights. All the tests on CPU etc seem to show no problem, it works great once the cycling finishes but obviously something is not right. This is still happening even after we replaced, like-for-like motherboard (ASUS Hero XII wifi) as we thought this might be the problem although obviously wasn't. We have run memtest, all OK, unplugged and reconnected everything, reseated CPU. It is becoming very frustrating as we can't seem to come to solution. 

Any ideas would be most appreciated!

 

Asus ROG Maximus Hero XII (wifi)

Corsair HX1200i PSU

i9 10900K

ASUS Strix 3070 OC GPU

Corsair Water Cooling for CPU

Corsair Vengeance RGB Pro 32 GB (2 x 16 GB) DDR4-3200 CL16 Memory

 

Cheers

[Jeppes]

Turn off fast start-up on windows.

[archerboy]

Thanks for reply, I believe my son tried this but I'll get him to do it again, cheers

[archerboy]

Hi Jeppes, thanks for the above advice, so far it seems to have worked, so keeping fingers crossed. Cheers

[archerboy]

I spoke too soon! 
Worked for two days and returned to power cycling. . Getting to the point of putting it in the bath.

[Digideath]

I've seen this before. I had a build years ago that power cycled like crazy befor it boot. Sometimes it would actually shut off during cycling. So I got a better psu and all of a sudden everything started working.

 

I'm not saying that's def what's wrong with yours but it's something to test.

[archerboy]

Thanks for reply. I think the next plan is to return the PSU to Corsair as we've tried everything else to no avail. it's so frustrating as the issue is not always consistent in how it manifests itself. This morning the thing maniacally power cycled and we swapped the two connectors over on the USB 2 header and it worked, although the flashing power leds on the GPU are still flashing. Weird. Cheers

[Guest]

This is normal for the board to cycle especially when running XMP or high memory frequency. All my ROG boards do that too. 

 

[archerboy]

Hi, thanks for reply. Do they continually recycle at times though? We have had both situations over the last couple of days. Sometimes it just keeps doing it and doesn't boot, other times it does it a few times and then boots OK. It seems one of those annoying issues that is difficult to replicate . Cheers

[archerboy]

SOLVED- Crap PSU! We seemed to have one of the 1% failed units