Question PC Desktop automatically turns on when plugged in. PC fan and LED lights on, but keyboard, mouse, and monitor not powered when PC is turned on.

[ancientbarnacle123]

Specs:
OMEN 40L Desktop GT21-0003na Gaming PC - NVIDIA® GeForce RTX™ 3080
Here's a descriptive video of what's exactly in my computer from HP Support.

View: https://www.youtube.com/watch?v=hZNVw2uJVIY&t=627s

• Processor Model Intel 12th Generation Core i7
• Processor Model Number12th Generation Intel Core i7-12700K processor
• Processor Speed (up to) 3.6 gigahertz
• Storage Type SSD
• Total Storage Capacity 1000 gigabytes
• Solid State Drive Capacity 1000 gigabytes
• System Memory (RAM)16 gigabytes
• Graphics NVIDIA GeForce RTX 3080
• Operating System Windows 11 Home

Motherboard description
HP name: HanaAOC

• SSID: 8949

Form Factor
Micro ATX, channel board exchangeable

• Dimensions: 24.0 x 24.0 cm (9.45 x 9.45 in)

Chipset B550
PSU:
OLD: HP 800Watts
NEW: (Today, I Just replaced it with ASUS ROG STRIX 1000W GOLD PSU)
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Problem:
Hey everyone,
My computer just turned off randomly yesterday when using it, then it turns back on and fans and LED are the only thing working, nothing on the monitor, keyboard, mouse. Keyboard and mouse LED lights turn on only when the computer is in sleep mode.

• PC starts up automatically when plugged in. When holding power button, it seems to go only in sleep mode. I have to turn it off by unplugging or using the power button on the ASUS PSU unit.
• Can't even get to the BIOS screen because monitor is blank.

Don't have warranty anymore. So upgrade or suggestions are welcome.
What I tried:

• Yes I did search up reddit, tom's guide, and quora for the past 2 days.
• I ordered a new PSU (ASUS ROG mentioned above), and reinstall everything to GPU and motherboard.
• I unplugged and re plugged everything back to the motherboard, except CPU and heatsink.
• Used a different old graphics card (GTX 960).
• Reseated the RAM.
  • I also tested it one ram at a time.
• Replaced the CMOS battery.
  • I did take off the CMOS battery and left it for 30 minutes to drain out the remaining power.
• I also tried turning on my PC without any graphic cards, and it is still automatically turning on.
• Unfortunately, I'm unable to directly connect the monitor to the motherboard because HP Omen HanaAOC doesn't allow that.

Results: All the actions mentioned above result in the same problem.
-PC starts up automatically when plugged in. When holding power button, it seems to go only in sleep mode. I have to turn it off by unplugging or using the power button on the ASUS PSU unit.

• I tested the monitor on my old computer, and monitor still works.

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What do you think might be the issue? Any suggestions? Thank you so much!

 

[Darkbreeze]

Try unplugging the wiring coming from the case front panel to the motherboard. ALL of the wiring coming from the front of the case. Hard drive and power LED cables. Power switch. Reset switch. USB cables going to the front USB ports. All of it to the front panel. Then plug it back in and see if it still does it. If it does, the motherboard must be the problem since the power supply was already replaced.

And, given how new that unit is it MUST be under warranty, so I would RMA the whole system unless you like spending money on things you don't need to be or unless for some reason you have no warranty on it.

 

[ancientbarnacle123]

Try unplugging the wiring coming from the case front panel to the motherboard. ALL of the wiring coming from the front of the case. Hard drive and power LED cables. Power switch. Reset switch. USB cables going to the front USB ports. All of it to the front panel. Then plug it back in and see if it still does it. If it does, the motherboard must be the problem since the power supply was already replaced.

And, given how new that unit is it MUST be under warranty, so I would RMA the whole system unless you like spending money on things you don't need to be or unless for some reason you have no warranty on it.

I will try that tomorrow, and you're correct on the warranty. I checked the best buy website and it said 15 days till return. Thought that was the warranty lol. I'll doublecheck with a nearby HP care center

 

[Darkbreeze]

Yes, with a 12th Gen Intel CPU in there, it can't be more than a year old so it pretty much has to be under warranty unless you bought it used, which clearly you didn't. I'd contact them right away.