i7-12700 Has to Power Cycle Twice Before It Will Boot

[imk]

Hello,
I have home built PC based on following that has been working for a year perfectly :
Win11 Pro 25H2
ASUS H610i-Plus-D4 BIOS 3401 
16gb Kingston Fury RAM
SAMSUNNG SSD 512gb  M.2 NVME MZVLB512HBJQ
Intel i5-12400

About a week ago I updated the BIOS  to 3801 and installed a new i7-12700
And now the system only seems to boot on a second power up attempt.

Inasmuch as I power the system on and wait for it to boot 10 or 15 seconds but the system does not POST or display the ASUS splash screen.
Only sign of life is the disk light shows varying brightness, so I have hold the power button until system power off, wait 10 seconds press power on and system boots fine and run all day perfectly.

I have returning the system to BIOS 3401 but system is same, I have also turned off Fast Boot in the BIOS but problem still same.

Any ideas please, many thanks in advance imk

[LeonWaksman]

1. Reset RAM modules.

2. Check the CMOS battery.

3. Reset BIOS to default settings.

4. Try to boot with all external devices disconnected.

Leon

[imk]

Morning Leon and thanks for the post,

Unpluged my two data disks last night.
This morning mancave was cold 17c but system POST'ed and got halfway thru booting Win11 then crached.
Powered off, waited,  powered on and system POST'ed and loaded Win11 and working fine for past 2 or 3 hours.

Am going to remove CMOS battery to completely BIOS setting, reseat RAM as have already reseated the CPU yesterday.

I have been doing PC's since late 80's for aviation and done 1000's of them into airport in 25 countries.
Been at PC's from XT all the way up to today and this is oddest problem I have seen.
Me thinks it is either faulty CPU or extra boot up load from i5  to i7 is too much for this motherboard VRM or PSU.
Will post back when have done above and system has cooled, maybe tomorrow morning

All best imk

[imk]

Latest update;
0200 this morning from cold system failed to boot with this i7 install
1000 this morning removed i7 fitted original i5 system booted after F5 setting defaults.
All this points at a faulty i7, will fit it to my standby ASUS H610i-Plus-D4 that is still on bios 3401
Will post again in day or two...
imk

[imk]

I think maybe final update:

Fitted this i7-12700 to my spare ASUS H610i-Plus-D4 MB BIOS 3401

Would not POST at all with 180w PSU in Mini ITX case.
So plugged in OCZ 600w PSU and after two or three attempts the system POST'ed and boot into Win11.
Left system playing videos for some hours and it ran perfectly.

Thought POST issues maybe be caused by excessive startup load on the VRM so turned CPU Max Power down for S1=65w and S2=100w

Put system into sleep state and switched the PSU Off, then power on the system
About 3 out of 4 power on's out of cold start sleep the system would POST and boot, sometime it took 3 attempts of cycling the power button.

So don't know what to think at this stage H610i-Plus-D4 VRM's not up to job or this i7-12700 has issues POST's.

Any thought most graciously received imk

[imk]

Problem Update:
After much research (and reverted to a SATA SSD for some tests) it seems these SAMSUNNG SSD 512gb  M.2 NVME MZVLB512HBJQ
Are a bit problematic when negotiating PCIe at POST so I have set PCIe mode to Gen 3 for m.2 NVMe
The system is now almost 100% post/boot reliable inasmuch as I lost count yesterday how many times it booted ok after a Power Off Sleep and Shut Down Restarts.
However this morning when system was cold, lounge temperature of 18c or so, the system froze half way thru booting windows.
On a 2nd power cycle the system didn't POST and on the 3rd power cycle the system booted OK and has had several Sleep Power off/on reboots and worked fine.

Why the system doesn't misbehave with an i3 or i5 but does with this i7 is work in progress.
As i have done all the obvious fiddles like reseating RAM and CPU, plus PSU and motherboard swapping

Maybe we have two faults, will update later if I find anything