Here is a receipe for boot from an older kernel, and how to set it to a default.
 

If you have a few Kernels in your system you can set manually what Kernel version will start:

  1. Reboot your PC with pressed Shift button for display GRUB after BIOS will start. You will see something like: GRUB start page

  2. Select "Advanced options for Ubuntu" and memorize index of this menu line(count starts from 0) On the picture index is 1

Select concrete Kernel

  1. Select concrete kernel for boot and also memorize index of this menu line(count starts from 0) On the picture index of chosen Kernel is 2

  2. Start system. This action is for one boot on concrete kernel. If you want to start from concrete Kernel all time you should do next steps:

4.1. Open and edit GRUB setup file:

sudo nano /etc/default/grub

4.2. Find line GRUB_DEFAULT=...(by default GRUB_DEFAULT=0) and sets in quotes menu path to concrete Kernel(Remember menu indexes from steps 2 and 3). In my system first index was 1 and second was 2. I set in to GRUB_DEFAULT

GRUB_DEFAULT="1>2"

Save file.

4.3. Update GRUB information for apply changes:

sudo update-grub

4.4. After reboot you automatically boot on Kernel by chosen menu path. An example on my machine 1 -> 2

4.5. Check Kernel version after reboot:

uname -r

 
Sent: Thursday, April 18, 2019 at 10:54 PM
From: "Brian O'Keefe" <okeefe@cybermesa.com>
To: nmglug@lists.nmglug.org
Subject: Re: [nmglug] Weirdness

Thanks again,

Tried them all to no avail

On 4/15/19 6:33 PM, Harold Furbiter wrote:
You could try:
sudo /sbin/init 6   (see if it reboots)
reboots to a blank, colored screen, no log in
sudo /sbin/init 1   (see if it give you a prompt)
Gives me a rescue mode prompt that I cannot use as I can't enter any of the options
 
maybe su to root and try init
sudo su - root  (you need '- root' to insure your path is root's)
 
you might try booting from a older or oldest kernel:
Can't access the grub menu for older kernels. Using shift key during boot just gives me the blank colored screen
 
dpkg -l | grep linux-image | awk '{print$2}'
 
Gives you a list of bootable kernels available on your system. Try booting from the oldest version.
Is there a way to reboot from a terminal with an older kernel as I cannot access the grub menu. this is a recent issue, within the last couple of weeks.
 
Cheers,
 
Sent: Saturday, April 13, 2019 at 8:32 AM
From: "Harold Furbiter" <wwcorigan@mail.com>
To: nmglug@lists.nmglug.org
Subject: Re: [nmglug] Weirdness
Then you have a corrupt kernel. On boot try booting to an older kernel.
 
 
 
Sent: Friday, April 12, 2019 at 6:15 PM
From: "Brian O'Keefe" <okeefe@cybermesa.com>
To: nmglug@lists.nmglug.org
Subject: Re: [nmglug] Weirdness

Thanks for the input Harold,

Same result, just hangs on the splash screen. Can't logout, esc. key does nothing, can't switch to a console. Just have to do a hard shutdown.

On 4/11/19 8:59 PM, Harold Furbiter wrote:
Out of curiousity have you tried init 0 ?
 
Sent: Wednesday, April 10, 2019 at 11:26 AM
From: "Brian O'Keefe" <okeefe@cybermesa.com>
To: "NMGLUG.org mailing list" <nmglug@nmglug.org>
Subject: [nmglug] Weirdness

Hi All,

Since I may not make meeting (niece visiting and Thurs. is her last day) I'm putting my issue out for comment and hopefully answers. As many of you know I used to updgrade instead of clean installs and did that since Ubuntu 6.04. I had also added many apps from third parties and also modified many, many conf files to keep things working. I had a meltdown and lost much of my data but following a partial recovery, thanks to a certain group member, I installed a clean version of 18.04 onto a new 1TB SSD. I have ot tinkered at all with 3rd party software nor modified any conf files or been a bad boy in any way!

My issue ids that I cannot shut down my box in anyway other than a hard shutdown. I also cannot restart it. I have tried the GUI option as well as switching to text mode and using "sudo shutdown now" or "sudo restart now". In those cases I get the splash screen with the "traveling lights" and Unutu but it hangs there. The traveling dots hang on the first dot of the splash screen and nothing happens. I had hoped that text mode would give give me an indication of the issues but I can't stay in that mode for some reason. 

Thanks for any help.

Brian

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