Dell Vostro 3750 often reboots instead of shutting down. Why and what to do?

Question

In German Windows 8.1 and Debian Live 10.3.0, when I tell my laptop Dell Vostro 3750 to shut down, it sometimes turns itself off properly (probably during initial work or after long do-nothing breaks, probably when the laptop is cold), but after it is used for some time (probably 10-60 minutes, I cannot tell exactly), it only reboots instead of turning itself off.

In Windows, I tried to shut down the laptop by:

• pressing Alt+F4 and choosing the power-off menu entry and

• running shutdown /s from the command line.

In Debian Live, I tried to shut down the laptop by

• choosing the power-off entry from the upper-right corner of the Gnome screen and

• running shutdown -h now as root.

So, it could be a hardware problem (e.g., due to the computer getting warm). Or the software (both in Windows and Linux) lost the ability to properly shut down that laptop in the course of software updates.

Yes, I

• turned off "quick boot" in Windows,

• set HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\PowerdownAfterShutdown to 1,

• loaded the default BIOS settings,

• checked that the only "... wake ..." option in BIOS setup (namely, wake from USB) is disabled,

• checked that the BIOS is at its latest version A14 available from Dell,

• checked that no alarm is set in the BIOS setup, and

• turned off the flag System Properties > Advanced > Startup and Recovery > System failure > Automatically restart in Windows.

As a test, I unplugged (in the off state) AC adapter from laptop, removed the battery, and waited for over 30 seconds. Then I reconnected the battery and the AC adapter. It resolved the issue exactly once: on the first boot and a shut-off command from Windows, the laptop indeed went off; the second try was with Linux, and the laptop rebooted when commanded to shut itself off. Subsequent attempts to shut off with either operating system resulted in a reboot.

As another test, in Windows I defragmented the hard drive, waited 10 to 30 minutes (the laptop remained on but did nothing), then issued powercfg /h off as an admin followed by powercfg /h on, and then commanded the laptop to shut itself off. Surprisingly, if indeed went off. I started it again, booting Windows, and shut it off again: it went off again. On the third time, I was out of luck: I booted Debian live, and from then on the laptop rebooted when commanded to power off.

The CMOS battery was replaced rather recently (about 20 months ago), and the clock has shown no sign of deterioration since then.

So, what next:

1. Is there any way to find out whether it is really a hardware problem?

2. Is there any workaround to turn the laptop off in a "soft way" (i.e., apart from pressing the power button and holding it for 5-10 seconds)?

Answer 1

• Unplug AC adapter from laptop, remove battery, and wait 30 seconds. Then reconnect battery and AC adapter. See if that resolves.

• The CR-2032 "CMOS" battery in your laptop may need replacing. This laptop is old.

• Old batteries sometimes cause weird issues. The BIOS/UEFI may have a battery health indicator - if your battery is old, consider replacing it or using the laptop without it and see if that makes the issue disappear.

• Make sure BIOS/UEFI is updated to latest version. You may try reflashing the latest version available.

• Almost all modern BIOSes/UEFIs have an option to automatically power on at a certain time on any days of the week you want. Make sure this option is disabled if available on your system. Also disable any Wake-on-LAN, Wake-on-USB, or other options.