I recently did a kernel update on a s2600cp server running Ubuntu 18.04.
When booting into the latest installed kernel version from GRUB. My monitor displays a blinking cursor in the top left corner, but is otherwise unresponsive. I tried ctrl + alt + f2 to drop into another terminal with no luck. After a couple of minutes the machine reboots itself.
I know the blinking cursor often indicates faulty graphics drivers so I tried adding the nomodeset boot flag with no luck. I also tried acpi=off and noapic and combinations of the three, but I still only get the blinking cursor.
I tried booting into recovery mode with the same results.
The only way I am able to log into the system is by booting into the older kernel. For now I can change the GRUB menu to boot into the older kernel by default, but I would like to know if there's any way for me to debug this issue any further. I would like to figure out what's going wrong, but there's no way for me to get any output at boot time.
**Edit: ** I've also removed the splash and quiet options from the GRUB entry.