System appears dead after shutdown when mem_sleep_default=deep is set (Dell XPS 8930)

[rbrucemccarthy]

Title: System appears dead after shutdown when mem_sleep_default=deep is set (Dell XPS 8930)

System:

• Linux Mint 22.3 Cinnamon
• Dell XPS 8930

Issue:
If the kernel parameter mem_sleep_default=deep is set, shutting down the system causes it to appear fully powered off, but it will not power back on using the power button.

Users may think the system has failed or the PSU/motherboard is dead.

Recovery requires:

• Unplugging the system
• Holding power button ~15 seconds
• Plugging back in

Fix:
Remove mem_sleep_default=deep from GRUB.

Suggestion:

• Add warning in documentation or update-grub process
• Detect unsupported deep sleep configurations
• Possibly default to safer sleep mode (s2idle) on desktops

This could prevent confusion and unnecessary hardware troubleshooting.