Blackscreen at boot, either because of memory upgrade OR full disk ?

**frederic-c** · December 8th, 2021

Hi everyone, I've been having trouble with booting on Ubuntu ever since I upgraded my memory ram stick, for roughly a month.

Machine : ASUS K501UB
CPU : Intel 17-6500U, dual core
GPU Nvidia GeFroce 940M
OSs : dual boot Win10/Ubuntu20.04
Memory : migrated from 4Gb+4Gb to 4Gb+8Gb
BIOS : UEFI

I have been booting on Windows without any problem so far, the memory working well for what it looks. However I am having black screen with blinking underscore right after the GRUB screen ever since when trying to boot on Ubuntu.

My guesses :
As I digged on forums, I suspected something had to do with the graphic drivers or memory compatibility.
To be noted, a disk occupancy might be responsible of the bug as far as I understand it. Indeed, the disk partition was quite full the days around the memory upgrade. The fact that the black screen happened right after the ram stick change could be a coincidence. Does it make sense to anybody ?

--DEBUG ATTEMPTS--

*RECOVERY BOOT

Booting on recovery, I receive the following message at the end of the process:

Attach1.PNG (488.4 KB)

*MEMTESTER

On a Deepin live usb, I ran memtest as followed:

Code:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install memtester
sudo memtester 1024 5

Attach2.jpg (50.7 KB)
It returned screens apparently stating evertyhing was great. Is it right ? (sorry for the poor quality of photos)

*RECOVERY TOOLS

On the recovery screen, the analyzer tools give the following messages: (those screens are in French in my machine. I hope it is understandable still)

-disk space-

Attach3.PNG (503.9 KB)

-memory-

Attach4.jpg (31.3 KB)

*NVIDIA DRIVERS

On a forum, I got the hint to reinstall nvidia drivers.
On recovery command line, I entered :

Code:

sudo apt-get update && sudo apt-get upgrade
sudo apt install nvidia-drivers-390

It returned the following messages :

Attach5.jpg (117.5 KB)

As a result, I now no longer boot on a blinking underscore, but a pitch black screen.

UPDATE:
Following the last struggle, I performed on recovery CLI a dist upgrade and installed a more recent nvidia driver:

Code:

sudo apt-get update && sudo apt-get upgrade
sudo apt-get dist-upgrade
sudo apt-get install nvidia-driver-455

I now can see the Ubuntu load screen! So there is that. Pressing F7, I see the boot process. With the same error message seen back in the Attach1.
I now end up in a black screen with a not-blinking underscore..

I am opening this thread as I really dont see where to look now as I cant grasp the problem. I am sorry if it is somehow redundant with other posts.