[SOLVED] New PC build powers on automatically ?

[AlexM197]

Hi Everyone.

I just upgraded my PC (kept old power supply), and there's an odd behaviour now. When I switch on the socket to which the PC is connected, the computer automatically boots. I've never seen this behaviour before, so not sure how to resolve it to ensure it doesn't happen.

Not sure if this helps, but it's a ASUS x670E-E motherboard and a Corsair HX1200i PSU

Thanks for any help

 

[pete_101]

Have you checked the front panel connectors on the motherboard to make sure you got them all connected to the right place? If so, them maybe the power button is faulty. You could check this by unplugging the connector to the power button and see if the problem persists.

 

[Lutfij]

(kept old power supply)
+
Corsair HX1200i
How old is the PSU in your build?

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list the specs to your build like so:
CPU:
CPU cooler:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:
include the age of the PSU apart from it's make and model. BIOS version for your motherboard at this moment of time?

 

[AlexM197]

Have you checked the front panel connectors on the motherboard to make sure you got them all connected to the right place? If so, them maybe the power button is faulty. You could check this by unplugging the connector to the power button and see if the problem persists.

I'll have a look at this, thanks!

(kept old power supply)
+
Corsair HX1200i
How old is the PSU in your build?


include the age of the PSU apart from it's make and model. BIOS version for your motherboard at this moment of time?

Apologies for not including this:

CPU: 7800X3D
CPU cooler: Corsair iCUE H150i Elite Capellix 360mm Liquid CPU Cooler
Motherboard: ASUS ROG STRIX X670E-E
Ram: 32GB (2x16GB) Corsair DDR5 DOMINATOR Platinum
SSD/HDD: Sabrent 1TB Rocket Nvme PCIe 4.0 M.2 2280/WD_BLACK SN850X 2TB M.2 2280/SanDisk Ultra II SSD 960 GB Sata III
GPU: ASUS ROG 4090 OC
PSU:Corsair CP-9020070-UK Professional Platinum Series 1200 W ATX/EPS Fully Modular Power Supply Uni
Chassis: Phanteks P600s
OS: Win11
Monitor: Nixeus EDG 27

The PSU is 3 years old

 

[AlexM197]

Turns out the issue was a BIOS setting. The "AFTER AC Power Loss" was set to "Power on," rather than "Last state"