Hey everyone, ive just installed zorin os yesterday and I am experiencing the same issues as this Screen flickers endlessly while starting the computer . I have tried using the nomodeset parameter but that didn't help. Here are my pc specs:
ThinkPad L430
i5-6300u
HD 520
Help would be appreciated, thanks in advance
You can check the following:
Is secure boot and fast boot switched off in the BIOS as well as fast boot in Windows (if you have dual boot)?
You can switch to XOrg and see if it is better then. To do this, restart the computer and click on your profile when logging in. A cogwheel will then appear on the screen. Set Xorg session there.
Are you using fractional scaling and what refresh rate? Switch off fractional scaling once and see if it is better then.
Welcome to the Forum!
Did You checked the Cable?
@Forpli Secure Boot was already disabled on my system. I also switched the session to Xorg as suggested, but unfortunately, I'm still experiencing the same flickering issue. Fractional scaling was already disabled. Refresh rate is 60 Hz
Sorry, i don't understand. What cable?
Oh, sorry. My Mistake. I see, You have a Laptop. I meant the Cable to the Monitor, but forget it. How is Your Refresh Rate set up?
Are you suffering flickering just only during booting, or does it continue once up and running?
Ah, got it. I'm using the laptops built in display so there's no external cable. My refresh rate is set to 60 Hz
During boot, the Zorin logo appears and then keeps flickering indefinitely. I have to forcefully shut down the system to get out of it.
I just did a websearch using searchterm "ubuntu 22.04 screen flicker"
Found this ask ubuntu thread: intel graphics - Screen flicker after fresh install of Ubuntu 22.04 - Ask Ubuntu
which links to these and other Launchpad bug threads which may be worth a read.
EDIT:
What graphics do you have on that L430?
hd 520
After a lot of tinkering, I found that holding the Shift key during boot prevents the screen from flickering, allowing the OS to start normally
Tried almost everything. Didn't work 
One of the posts in the bug thread says "I can also confirm that the kernel 5.13.0-20-generic works without an issue"
I know that is a really old kernel, but from my reading it seems the flicker problem occurs with bad/regressed kernels since then.
I am not sure where you will get that 5.13 kernel from, but others here may know.
Over Mainline it could be available but the Problem is that it isn't a LTS Kernel. So, it doesn't get Updates anymore. But maybe the 5.15 Kernel could be worth a Try.
@XPstarcool: If You want try the 5.15 Kernel, here is describted how to add the Mainline Tool:
From what I read on the bug posts, 5.15 kernel would have the regression, so may not be suitable.
If the work-rounds suggested in those bug posts (e.g. adding i915.enable_dc=0 intel_idle.max_cstate=2) do not help, then maybe have to wait for a permanent fix for later kernels.
There are several Ubuntu screen flicker bug threads, but seems many are duplicates of Bug #1958191.
Bug #1958191 is listed as "Confirmed" and "Important" but "Unassigned" whatever that means.
EDIT: @XPstarcool thinking aside. Is your BIOS up-to-date?