Why did Precision 7760 turn itself on?

No, already have fast starup turned off. I had a problem with an early 77xx where it kept triggering bitlocker recovery to have fast startup on for some reason, so I've turned it off by default every since. I also like the uptime to show the time since last power on in the task manager, so I just always set fast startup to off on my dell precision laptops.

 

Thanks very much. Will give this a try tonight to reproduce as testing once a month is really difficult. I didn't think of changing the bios time to simulate! Thanks!

Do I just click "load defaults" at the bottom of the bios screen to restore the factory defaults, or do I have to do more? Have to think this through carefully as I don't want to mess up the os when doing this.

The only non-stock part I have installed are two Samsung 980 Pro SSDs, one for OS and one for data. I have the Dell FIPS fingerprint reader in the palm rest not in the power button. I don't have the dell stock ssd unfortunately at my location, so it will take me a bit to get that drive for the exact factory config. I'd be surprised if a samsung ssd could turn on a dell precision at a specific time, but I guess I'm firmly in the "surprised" territory now as I really expected it would not happen again this morning! It would be wild if the samsung ssd had some internal maintenance scheduler that ran at 8:24:11 even when the dell is turned off somehow tripping it to turn on ... (Samsung Magician shows the samsung ssds as Genuine and on current firmware.)

 

Changed the system time in BIOS to 8:20 AM. Booted, shut down at what the system thought was 8:22 AM. Then the Precision turned itself back on by itself for no reason again at what it thought was 8:24:11 again. So it appears I can reproduce this by changing the system clock to the 18th slightly before 8:24:11.

 

I think next I will try removing the two SSDs so there is no software installed whatsoever. Then I'll see if it still boots by itself with only what is in the Dell laptop itself.

 

I've removed the two samsung ssds.

With AC power connected and no SSD drives installed and nothing connected via any external port, the Precision 7760 still turns itself on at 8:24:11

 

Winner! But I don't know what it means ???

The auto-start does not happen if the the Dell AC adapter is disconnected (the one which shipped with the 7760.)

 

Tried it a few more times on and off AC power, and it's conclusive that the AC adapter has to be connected for this phantom auto-on to occur at 8:24:11. Every time on battery it did not occur, and every time on AC power at 8:24:11 it did occur.

 

I went into BIOS and chose "Load Defaults" at the bottom and chose Bios Defaults on the left.

The options were
Bios Defaults | Last Known Good | Custom User Settings | Factory Defaults

I loaded Bios Defaults saved and then powered down. Entered bios again and set clock to 8:20 AM and saved and rebooted. (the defaults obviously loaded as it tried to https boot but there is no external connection to it so I got a hard drive not installed message) Powered down.

Again at 08:24:11 the system powered on by itself.

 

This is strange. Did you also try and clear the residual power? Did you contact dell support to see what they say? Do you happen to have a dock and if so, does it happen with that as well (power via the WD19DCS)?

 

I disconnected the battery and held the power button for 5 seconds to clear the residual power. I don't have a dock though.