Question PC when switched off wont POST only after CMOS clear and removing mouse connection and waiting

[Spartan1341]

Recently built my second pc and have been having issues with powering it on. The system when switching off turns off power to my keyboard and mouse and the mobo aura goes back to default. The system then refuses to switch on without cmos clear unplug mouse and wait. It is not consistent sometimes I wait 10 mins sometimes hours for it to switch itself on.

For periods it is fine and will run as normal switching on and off normally. However recently it is back to playing up.

When the power button is pressed it does nothing + no fans spin.

I don’t have any mobo error lights on to guide the issue and am stumped.

My parts consist of:

• AMD Ryzen 5 7600X 4.7 GHz 6-Core Processor
• Asus ROG STRIX B650-A GAMING WIFI ATX AM5 Motherboard

• Crucial RAM 16GB DDR5 5200MHz

• Samsung 970 Evo Plus 2 TB M.2-2280 PCIe 3.0 X4 NVME Solid State Drive
• Asus DUAL OC GeForce RTX 4070 12 GB Video Card
• Corsair RM750 750 W 80+ Gold Certified Fully Modular ATX Power Supply

Everything I have done to diagnose the issue (might have failed to list a few more as have done a lot):

1. Reseated RAM (all slots, all configurations (single and dual)) and graphics card
2. Booted without GPU installed.
3. Removed CMOS to try and reset BIOS.
4. Tried to jump start mobo but no response.
5. Tried to paper clip test PSU
6. Tried to boot with minimal connections to mobo
7. Loosened CPU fan
8. Recently replaced RAM
9. Tried it with fast start up on and off
10. Checked power connections for faults

I feel like I have tried everything and would like a few ideas, if possible, to help.

The PC runs fine when on its just switching off causes it not to go back on. I think changing some settings in software and BIOS may be in order, but I am not too sure what will help this issue.

 

[nvidia_loyal]

Are you sure you have connected the power cable to the right pins on the motherboard? I once did that, and afterwards, my PC turned on

 

[rgd1101]

Question - PC refuses to conduct BIOS checks, after randomly switching off?

Recently made my second ever PC after 8 years. It was running fine in Win 11 and I left it to start downloading my apps ect. When I returned, it had powered off and now refuses to switch back on. I have literally tried to reseat everything on the rig (except CPU) but it refuses to boot. It...

forums.tomshardware.com

using case motherboard standoffs ?
test it outside the case?

 

[Spartan1341]

Question - PC refuses to conduct BIOS checks, after randomly switching off?

Recently made my second ever PC after 8 years. It was running fine in Win 11 and I left it to start downloading my apps ect. When I returned, it had powered off and now refuses to switch back on. I have literally tried to reseat everything on the rig (except CPU) but it refuses to boot. It...

forums.tomshardware.com

using case motherboard standoffs ?
test it outside the case?

Yes and yes issue persists

 

[rgd1101]

latest motherboard bios?
are you using any power cable not from the Corsair RM750?
test with a different psu?