Attempted to improve my GPU, but the system is no longer booting.
Attempted to improve my GPU, but the system is no longer booting.
Someone could assist me? I attempted to swap my 1060 6gb for a new 4070 card, but now my computer won't boot and it's showing a red light for "CPU" even though I haven't touched the CPU.
Z590 UD AC motherboard with i7-11700k CPU and an 850W power supply. I previously had a 1060 6GB GPU and upgraded to a 4070.
I just installed the 4070, yet the system still won't start and the motherboard displays a "CPU" light. All fans are spinning, the GPU is on, but the front fan LEDs stay off and the monitor fails to detect anything.
I didn’t touch the CPU at all (it’s covered by a large fan cooler), so I’m unsure what caused the issue or how to resolve it.
Has anyone encountered this before? Why would the CPU light activate during a GPU change?
What I've tried so far hasn't helped:
- Reinserting the old GPU.
- Disabling the GPU entirely.
- Reseating both RAM sticks (16GB x 2).
- Testing one RAM stick at a time.
- Leaving the motherboard battery out overnight, then reinserting it.
- Verifying all power cables are securely connected.
- Temporarily disconnecting/reconnecting the "CPU" power cable on the motherboard (the red light persists whether the power cable is plugged in or not).
- Inspecting the PSU power cords for looseness.
They remain firmly connected.
I’m uncertain what to do next. I really prefer not to replace the motherboard or PSU just yet. Everything worked perfectly before, there were no sparks, and I changed the graphics card while the PSU was off and unplugged.
The only step left is to examine the CPU itself, as it’s protected under a large air cooler.
Set up the new graphics card, ensuring it is completely seated and all necessary power connections are in place, and then proceed.
BIOS Hard Reset process
Turn off the device, switch off the power supply unit and detach the PSU cable from the wall or power source.
Take out the motherboard CMOS battery for roughly three to five minutes. In certain situations, you might need to remove the graphics card to access the CMOS battery.
While the battery is removed, keep pressing the case power button continuously for 15 to 30 seconds to discharge any remaining charge in the CMOS circuit.
Once the time has passed, reinsert the CMOS battery, making sure to place it correctly as it was removed.
If you had to remove the graphics card, you can now reinstall it, but be sure to reconnect all power cables and your display cable.
Reattach the power supply cable, turn the PSU back on, and restart the system. It should show the POST screen and provide options to enter CMOS/BIOS configuration.
Enter the BIOS setup program and adjust the boot settings for either the Windows boot manager or legacy systems, depending on the drive where your operating system is installed.
Save your changes and exit. If the system successfully POSTs and boots, continue by returning to the BIOS to configure additional settings such as Memory XMP, A-XMP, D.O.C.P profiles, fan profiles, or other custom configurations that may have been lost during the reset.
In certain scenarios, after entering the BIOS, you might need to select Optimal default or Default values and then save your settings to fully reset the BIOS and recreate the hardware tables.
Thank you for your assistance, but the attempt failed.
I followed these steps:
- Removed the GPU (previously had an old one).
- Extracted the motherboard battery (a round coin-shaped component).
- Waited 5 minutes.
- Turned the computer on and off repeatedly for more than a minute each time, plus rapid presses afterward.
- Installed a new GPU model 4070.
- Connected the PSU back to the computer and tried booting up.
The monitor displayed its power indicator but never showed anything on the screen. It said "no input found" and shut off after ten seconds.
I also switched from HDMI to DisplayPort, but the same problem occurred—monitor detected a connection but didn’t show anything and turned off with "no input detected."
The red "CPU" light stayed lit continuously, while the front LEDs and mouse/keyboard LEDs remained off as usual since the issue began. The new GPU had all its lights on and its fans operating normally.
If the red CPU light appears, verify that all power connectors are securely connected, particularly the 4+4 pin EPS/CPU connector along the board's top edge, ensuring nothing is missing. If you haven't handled the CPU or cooler and it was functioning previously but now shows a red light, something must have changed. This indicator doesn't turn on randomly, even though a CPU issue could explain its behavior through PCIe lanes. The first step is to confirm you have the latest stable motherboard BIOS version installed.
The 4-pin slot isn't mandatory; it's mainly for extreme overclocking purposes. You could try connecting the CPU with an 8-pin cable to another slot on the power supply unit. Many PSU models allow swapping the CPU and PCIe ports. This raises the question of which power supply you're using.
Do not need to remove all items from the board - proceed with updating BIOS and continue from there.