Sleeping robot.

[Xenon The Noble]

https://steamcommunity.com/sharedfiles/filedetails/?id=3003015899
What's with this big guy? Found it in the northwest area of the commonwealth. Found one somewhere else in another play through but thought it was a glitch. . It's not that child trader's robot, no kid in the area. Did the kid die and the robot shut down? I don't seem to be able to interact with it, it just sits there.
I'm going to call him Marvin,because he seems depressed.

[Ihateeverybody]

Only non active robot I can think of is the one in the scrap yard near Sanctuary. There is an activation tape in the small maintenance building on that lot. Your picture doesn't look like that location though.

If that robot is named Gus, its the kids robot. I can't think of any other Sentry Robots that are non aggressive.

There are some robots like the one near Vault 94 and at the National Guard Training Yard that require you to do something before they go aggressive.

[DouglasGrave]

If it's not in a set location, there is at least one random encounter type that has a bunch of (I think) Rust Devils initially tinkering with an inactive Sentry bot.

I don't remember offhand whether it activates and fights alongside them or attacks them, but if something happened to distract the Rust Devils, it could have been left there alone.