Boot problems - have to use recovery mode every time

[01pjf]

Many thanks for your answer.
I have discovered a couple of things tonight.
Linux mint standard live install does the same thing, with flashing writhing on the screen (but different)
The only way out from Mint or LL default boot is to press and hold the shut-down button and re-start.

This Laptop used to work fine on default install, and then I upgraded from 5.15.0-28. That's when this lot started. It is a bit familiar, as I get the same thing when I try to install Raspian on my Raspberry Pi4. I've ended up trying all the Raspian versions on the live web install system with the same result, and installed Ubuntu on my Pi which runs fine.

So on my Laptop, I invoked LL default boot, and everything was fine until I typed in my password, when it played the tinkly jingle, briefly displayed my desktop screen image, then went to flashy, writhy mode, followed by blank screen of death with backlight on.
No mouse cursor, or panels visible.
I followed your instructions, after a dry run through in compatibility mode to see how long it took to be able to type, and then, after a 20s pause held the off button down till the system shut down. Then I rebooted into compatibility mode and looked for the tee report.txt file in Home.
I was sad to see that it was not present, so it appears that there is no activity behind the scenes, I think. Or I got the timing wrong, but I don't think so.
A shame - I was hopeful of some way forward.
Thanks for your help, though
Pad

PS when I'm in compatibility mode, inxi  reports
Device-1: Advanced Micro Devices [AMD/ATI] Stoney [Radeon R2/R3/R4/R5 Graphics] driver: N/A
          Display: x11 server: X.Org 1.21.1.4 driver: ati,vesa unloaded: fbdev,modesetting,radeon resolution: 1920x1080~77Hz
          OpenGL: renderer: llvmpipe (LLVM 15.0.7 256 bits) v: 4.5 Mesa 23.2.1-1ubuntu3.1~22.04.2

Does that help?

Has this set up ever worked properly without the flash and writhe and dark display ?
If so, what changed ?
How do you exit from this state ?

If you think the system may be working under the dark display you could try things 'blindly'

For example
Press Ctrl Alt T together
Type in

Code:

inxi -Fxxx | tee report.txt

Followed by return

Then try pressing Ctrl Alt F2 together.
If things are working, this may switch from the GUI to a terminal type login at which you can enter your credentials.
If it doesn't access the desktop using the recovery mode.

Either way, check for the file called report.txt in your home directory.
If it is there, it proves the system is working blindly and may show what graphics drivers are loading in non-recovery mode.
The command you run blindly can be adapted to get other diagnostic information.