Red CPU light on Motherboard

Hunkydunky

New member
Hi all :)

I've only had my new PC several weeks and it has been working flawlessly until now!

Just yesterday I attempted to boot my PC - All RGB lights came on (Nothing seems to be missing) however the PC does not even get to the boot screen - There is a red flashing light labelled 'CPU' on my motherboard. The AIO cooler I have is all lit up red and once I attempted to re-boot to see if it'd fix itself, the AIO screen has a constant caution sign showing whereas before there was nothing when powered off.

On closer inspection of the CPU light on the motherboard, it may be hard to see but it seems to have '301' written underneath. Not entirely sure if it's related but attaching photo just in case.

Attaching photos and specs:

Case
CORSAIR 5000D AIRFLOW TEMPERED GLASS GAMING CASE
Processor (CPU)
Intel® Core™ i9 24-Core Processor i9-13900K (3.0GHz) 36MB Cache
Motherboard
ASUS® ROG STRIX Z790-F GAMING WIFI (DDR5, LGA1700, USB 3.2, PCIe 5.0) - ARGB Ready
Memory (RAM)
32GB Corsair DOMINATOR PLATINUM RGB DDR5 6000MHz (2 x 16GB)
Graphics Card
24GB NVIDIA GEFORCE RTX 4090 - HDMI, DP
Graphics Card Support Bracket
PCS ARGB GRAPHICS CARD SUPPORT BRACKET
1st M.2 SSD Drive
2TB SEAGATE FIRECUDA 530 GEN 4 PCIe NVMe (up to 7300MB/R, 6900MB/W)
Power Supply
CORSAIR 1000W RMx SERIES™ - MODULAR 80 PLUS GOLD, ULTRA QUIET
Power Cable
1 x 1.5 Metre UK Power Cable (Kettle Lead, 1.0mm Core)
Processor Cooling
CORSAIR iCUE H150i ELITE LCD XT RGB CPU Cooler
Thermal Paste
ARCTIC MX-4 EXTREME THERMAL CONDUCTIVITY COMPOUND
Extra Case Fans
3x Corsair LL120 RGB LED Fan + Controller Kit
Sound Card
ONBOARD 6 CHANNEL (5.1) HIGH DEF AUDIO (AS STANDARD)
Network Card
10/100/1000 GIGABIT LAN PORT
USB/Thunderbolt Options
MIN. 2 x USB 3.0 & 2 x USB 2.0 PORTS @ BACK PANEL + MIN. 2 FRONT PORTS
Operating System
Windows 10 Home 64 Bit - inc. Single Licence
Operating System Language
United Kingdom - English Language
Windows Recovery Media
Windows 10/11 Multi-Language Recovery Image - Unlimited Downloads from Online Account
Office Software
FREE 30 Day Trial of Microsoft 365® (Operating System Required)
Anti-Virus
Norton 360 inc. Game Optimizer - Free 90 Day License
Browser
Google Chrome™
Warranty
3 Year Standard Warranty (1 Month Collect & Return, 1 Year Parts, 3 Year Labour)
Delivery
2 - 3 DAY DELIVERY TO REPUBLIC OF IRELAND
Build Time
Standard Build - Subject to stock availability on pre-order products
Welcome Book
PCSpecialist Welcome Book - United Kingdom & Republic of Ireland
Logo Branding
PCSpecialist Logo
 

Attachments

  • Red CPU light.jpg
    Red CPU light.jpg
    718.5 KB · Views: 163
  • Powered on.jpg
    Powered on.jpg
    1,023.5 KB · Views: 142
  • Powered off.jpg
    Powered off.jpg
    321.2 KB · Views: 120
  • CPU light 301.jpg
    CPU light 301.jpg
    524.6 KB · Views: 157
Last edited:

B4zookaw

VALUED CONTRIBUTOR
Puzzling. If the CPU failed, I’d still expect the AIO to function, and not show signs of error. And similar if the AIO failed the system should still boot, but might eventually shutdown if the CPU hit max temp.

Any messages displayed in BIOS on boot?
 

SpyderTracks

We love you Ukraine
If the AIO failed, it might depend how the system views the failure...if the system decides that there's no functional cooler, then that might possibly be why....when I've tried doing troubleshooting in the past and disconnected the CPU fan, then the system point blank refuses to boot
That should still boot to a BIOS warning page.

It's possible the OP has a screen that isn't compatible with BIOS output which is why it's not displaying.
 

Hunkydunky

New member
That should still boot to a BIOS warning page.

It's possible the OP has a screen that isn't compatible with BIOS output which is why it's not displaying.
That's a good shout - I've never had issues with my monitor showing BIOS on my previous PC but when I get home after work, i'll chuck a different monitor on to see if that yields any further results, then shout with an update back here :)
 

B4zookaw

VALUED CONTRIBUTOR
Might also be worth taking the side off the case and checking the cooler connection on the motherboard...it's possible it came loose during transit...sometimes things can come loose but take a while to cause an issue. I think it plugs direct in to the motherboard with your configuration:

View attachment 36628
No, Corsair AIO is all controlled via controller that connects to USB header. It connects to CPU FAN header to report a speed to allow it to boot as others have mentioned, but the fan headers don’t control the pump or fans in any way.
 

Hunkydunky

New member
Howdy gents, thanks a million for all of the replies so far :)

Update: Unfortunately BIOS does not show even on another monitor using Displayport and including a third monitor connected by HDMI - No output whatsoever.

I've just noticed that my keyboard and mouse don't get any power from the PC at all either from any of the USB ports on the motherboard.

Live update to the update: I attempted to plug in my phone using the USB C port while the PC was powered on to test if there was any power output whatsoever and as soon as I plugged in the phone, it took several seconds for the phone to charge and then... the motherboard gave one beep and the entire PC came back to life...?! What is this sorcery?! :ROFLMAO:

I've since restarted the PC several times throughout the day at random just to test to see if charging my phone really did fix the issue and.. it seems to have. Everything is back to normal.

Bizarre.

Anywho, unless it kicks the bucket again, a big thank you to everyone for your time :D
 

RichLan564

Bright Spark
I'm not sure I'd be happy with that. I would call PCS and talk this all through with them. It sounds like there might be a flaky motherboard issue to me......
That was my thought exactly, plugging a phone into a USB-C port isn't going to make a PC more likely to boot, not unless there is something else seriously amiss
 
Top