LL4 - boot failure following switch from Intel to nVidia card (390 driver)

[m654321]

I have LL4.0 temporarily multi-booted with Windows 8, Manjaro, Linux Mint and Elementary OS. The laptop I have is setup[1] in my signature below, which is also listed on my forum profile on the left side of this forum window. The laptop has dual video cards installed (Intel & nVidia) and so has Optimus installed for LL. 

LL4 has been working fine with the Intel card. However, when I switched to the nVidia card (the proprietary nVidia 390 driver is installed), and rebooted, LL just ended up frozen on a blank black screen, failing to boot fully, with a small static white 'cursor' visible in the top left  corner of the screen.  Is this the problem that English Bob (EB) mentioned in his video at the forum link  https://www.freecinema2022.gq/forums/tutor...ard-users/  ? 

I observed that the same thing happened with Linux Mint 19, when switching from Intel to the nVidia 390 driver.  In contrast, I found that this didn't happen with Elementary OS (also Ubuntu-based like LL & LM) - the difference here is that the proprietary nVidia driver installed on Elementary is not 390 but the 384 version.

In the above video link, EB advised that the 390 driver should be replaced by the 396 driver, as the 390 one can "just brick up your system" - he emphasized it was a fault of the nVidia driver, not the operating system. My observations described above - with LL, LM and Elementary - seem to support EB's view. Have you experienced a similar issue with the nVidia 390 driver?

Assuming I can get out of this, using the terminal in the live environment (rather than having to reinstall LL), should I follow English Bob's advice by replacing the nVidia 390 driver for the 396 version?  At first impression, this would appear to be a no-brainer. The only problem is that when I installed the 396 driver previously, according to EB's method, it appeared impossible to switch back to the Intel card, as the NVIDIA X Server Settings app wouldn't open, as I reported previously in post #3 of the above forum link.

Many thanks in advance for any advice on this one, which I'm sure must have affected at least some of you with the dual nVidia/Intel video card setup.

All ideas welcome and much appreciated, as always  8) 

[m654321]

Just updated post #1, to include observations I've just made with 2 other Ubuntu-based distros.

Looking forward to receiving your views & comments.

[kpanic]

If you use Nvidia proprietary software, ask Nvidia.

I hope someone here can help but it has nothing to do with LL. You have been warned
already about using proprietary drivers and you have accepted the Nvidia License.

Try switching back to Linux 'nouveau' driver: Start -> Settings -> Install Drivers

[m654321]

You have been warned already about using proprietary drivers. I hope someone here can help but it has nothing to do with LL

Thanks kpanic for your reply.
Yes it's an nVidia problem not an OS one, as emphasized in post #1.

I checked the LL Help Manual, but found no "warning" about the nVidia 390 driver under the Graphics Drivers section. 
Maybe I was looking in the wrong section. The only reference I could find on this forum, regarding such a warning, was English Bob's tutorial, discussed above.
When Jerry replied to EB's tutorial, he didn't highlight EB's take-home message about the nVidia driver - this issue
was just one of several points that EB addressed.

I'm surprised that I seem to be the only one reporting this problem, as there must be several LL users out there
with an nVidia Optimus PC - maybe all those concerned just followed EB's tutorial (?) but the caveat was that
that I found switching back to the Intel card problematic, as I highlighted in EB's thread.

Maybe I should have posted this message in the 'Discussion' section rather than in the 'Help' section ...

[bitsnpcs]

[member=458]m654321[/member] if you use the @ tag with the members username it may notify them if their email settings include that, or otherwise add it to the mentions category of their profile.
They may have advice about their tutorial that could be useful for you.

[m654321]

[member=458]m654321[/member] if you use the @ tag with the members username it may notify them if their email settings include that, or otherwise add it to the mentions category of their profile.
They may have advice about their tutorial that could be useful for you.

Many thanks bitsnpcs  8)
I think I'll do what you suggested (i.e. [member=7126]EB[/member]) to see if he can suggest to me how to get round the apparent failure to switch back to the Intel driver from the nVidia 396 one.  Haven't been here for a while on any regular basis - I hope you're well. A lot of the folk I used to know here I don't see anymore, e.g. goldfinger, wirezfree, etc ... I guess folk move on as they get more confident with using Linux, and try other distros which might be more challenging.

[bitsnpcs]

Glad it is useful [member=458]m654321[/member] 
I am well thank you, and yourself I hope ?

Edit -
I see on the main forum page [member=106]Wirezfree[/member] logged in this last 2 weeks, last post I remember he was having an issue with posting on the forum, I am unsure if this was solved.
goldfinger may be busy he is around a while ago as he and Scott helped me with an external hdd issue I had due to the junk the manufacturer added to it.

[MohamedKhaled]

[quote author=bitsnpcs link=topic=5787.msg43122#msg43122 date=1536920570]
[member=458]m654321[/member] if you use the @ tag with the members username it may notify them if their email settings include that, or otherwise add it to the mentions category of their profile.
They may have advice about their tutorial that could be useful for you.

Many thanks bitsnpcs  8)
I think I'll do what you suggested (i.e. [member=7126]EB[/member]) to see if he can suggest to me how to get round the apparent failure to switch back to the Intel driver from the nVidia 396 one.  Haven't been here for a while on any regular basis - I hope you're well. A lot of the folk I used to know here I don't see anymore, e.g. Goldfinger, wirezfree, etc ... I guess folk move on as they get more confident with using Linux and try other distros which might be more challenging.
[/quote]
I don't know actually I never changed a GPU but recently i added a new stick of ram and I had all sorts of weird bugs in both Linux and windows until i totally formatted windows (and Linux too) and reinstalled I also read online that you should always reinstall your os after hardware changes some people even say that this is because when you install any os it gets tailored for your resources during the setup so new hardware could cause these customizations to break I know its bad but I think that the easiest way is to reinstall all your oses again