Ethernet port and GPU doesn't seem to be used after accidentally unplugging power supply cable
https://askubuntu.com/questions/1554882/ethernet-port-and-gpu-doesnt-seem-to-be-used-after-accidentally-unplugging-powe
I accidentally unplugged the power supply cord while I was using my desktop computer (Ubuntu 24.04.2 LTS).
After booting my PC, I noticed two uncommon behaviors:
- The Ethernet cable was not being detected. I can assert this because normally the
ip address would similar to 192.168.1.XXX under a certain network interface, but when I executed that command, that IP address was not shown. I tried executing ping www.gnu.org, but I got ping: www.gnu.org: Name or service not known.
- After logging-in, the screen resolution was very low. I think this happened because the GPU was not being used.
I did a cold reboot, but those two behaviors persist.
I thought this was a hardware problem related to the motherboard caused by the sudden interruption of power. To discard this possibility, I started Ubuntu 24.04.1 LTS using a bootable USB with the installation image and the Ethernet port was being used (I can assert this because I could search information for the Internet, this PC doesn't have a Wi-Fi card) and the resolution of the GUI was high and smooth which makes me think that the GPU was being used. I disconnected the USB and rebooted my computer but the two problems described above persisted. I find it strange that the Ethernet port is used while using the USB, but it is not used while starting Ubuntu which is installed on my desktop computer.
Please let me know if you need further information or the output of some command to troubleshoot this issue and I will insert it at the bottom of this question.
UPDATE (2025-08-22T15:29:17+00:00)
I created a question on Ubuntu Forums: https://discourse.ubuntu.com/t/ethernet-cable-and-gpu-doesnt-seem-to-be-detected-after-a-power-outage/66729
UPDATE (2025-11-18T18:41:55-0500)
I am having the same issue, but this time, the problem was not caused by a power outage, but because I accidentally pressed the power button while my system was on. When I turn on my system, the login screen is shown at a very low resolution (it seems 800x600)
The post on Ubuntu Discourse had some relevant information to solve the issue, but as of time of writing, when I click on the link, the following message is shown: "Oops! That page doesn’t exist or is private.". I have some vague memories of the answer of that post:
These are the steps that I followed this time to troubleshoot the issue:
- Edit grub configuration file
Set the following variables in the configuration file:
GRUB_TIMEOUT_STYLE=menu
GRUB_TIMEOUT=10
- Execute "sudo update-grub"
- Turn off system
- Turn on system
- In GRUB menu, press "e". Then, press "Advanced options for Ubuntu". The following options were shown:
Ubuntu, with Linux 6.14.0-34-generic
Ubuntu, with Linux 6.14.0-34-generic (recovery mode)
Ubuntu, with Linux 6.14.0-33-generic
Ubuntu, with Linux 6.14.0-33-generic (recovery mode)
I selected "Ubuntu, with Linux 6.14.0-33-generic". I inferred the GPU was correctly detected because the login screen was shown in the appropriate resolution: 2560x1080.
sudo apt update
sudo apt upgrade
- Turn off computer
- Turn on computer
The problem persisted.
- Turn off computer.
- Turn on computer.
- In GRUB menu, press "e". A new option was added in "Advanced options for Ubuntu":
Ubuntu, with Linux 6.14.0-35-generic
Ubuntu, with Linux 6.14.0-35-generic (recovery mode)
Ubuntu, with Linux 6.14.0-34-generic
Ubuntu, with Linux 6.14.0-34-generic (recovery mode)
Ubuntu, with Linux 6.14.0-33-generic
Ubuntu, with Linux 6.14.0-33-generic (recovery mode)
When I selected "Ubuntu, with Linux 6.14.0-35-generic", the problem persisted.
I will be using "Ubuntu, with Linux 6.14.0-33-generic" for the time being.
UPDATE (2025-11-18T18:59:37-0500)
I checked my mail and I was able to find the messages from the post. The user who replied my post recommended executing sudo apt dist-upgrade. So, I followed these steps:
- Turn on computer.
- In GRUB menu, press "e"
The following options were shown:
Ubuntu, with Linux 6.14.0-35-generic
Ubuntu, with Linux 6.14.0-35-generic (recovery mode)
Ubuntu, with Linux 6.14.0-34-generic
Ubuntu, with Linux 6.14.0-34-generic (recovery mode)
Ubuntu, with Linux 6.14.0-33-generic
Ubuntu, with Linux 6.14.0-33-generic (recovery mode)
I selected "Ubuntu, with Linux 6.14.0-33-generic".
- Log-in
- Execute
sudo apt dist-upgrade
- Turn off computer
- Turn on computer and wait for the timer in the GRUB menu to finish so that the default option is selected
I concluded that the problem was solved because I could see the login screen in full resolution: 2560x1080.
- Revert the changes that I did in
/etc/default/grub so that the GRUB menu is not shown whenever I turn on my computer.
Change from:
GRUB_TIMEOUT_STYLE=menu
GRUB_TIMEOUT=10
to:
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=0
- Execute
sudo update-grub.