My Acer laptop (Ubuntu 18.04.3 LTS) fails to boot with new kernels 5.0.0-23 and 5.0.0-25. It boots normally with the old kernel 4.18.0-25.
Kernel 5.0.0-23 was installed prior to rebooting on 8/6/19. Kernel 5.0.0-25 was installed today (8/13/19).
I had been periodically booting with kernel 4.18.0-25, running Software Updater, and seeing if that fixed the problem. It didn't. (I am currently using a different computer for most purposes.) Today Software Updater installed the newest kernel, 5.0.0-25. When I restarted the laptop after the update, booting failed in the same way as it did for 5.0.0-23.
Now I will keep the laptop disconnected from the Internet, and not allow any more updates until I find out how to prevent updates from removing old kernels. I don't want to lose 4.18.0-25. I expected it to be gone today after the update, since updates had been saving only one old kernel, but fortunately it is still there. (Three kernels are present.)
Here is a short description of the problem.
When I boot with kernel 5.0.0-23, the screen goes dark and the power light turns off about 20 seconds after I select Ubuntu from the Grub menu.
When I boot with kernel 5.0.0-23 in recovery mode, the same thing happens after about 80 seconds, which is well after the Recovery Menu appears. The Recovery Menu screen has a few boot messages scattered diagonally across it, and has some other display problems.
History: On Tuesday 8/6/19, Software Updater appeared, and told me that it had updates and that the computer needed to restart to finish installing previous updates. I selected "Remind Me Later" but went ahead and restarted the laptop, which failed when booting, as described above.
This is dual-boot with Windows 10. Windows boots normally. The Ubuntu 18.04.2 LTS boot/install USB stick that I used for installing Ubuntu boots normally.
Acer Aspire 3 A315-51-361T (purchased new about a year ago)
Ubuntu 18.04.3 LTS
Secure Boot is enabled
What might be causing this problem? And what should I do about it?