DELLPRECISION 7510 RANDOM SHUTDOWN

Greetings all,

I've been using HP until someone recommended a Dell mobile workstation which I purchased fairly used.

The first month was okay until the second month it started shutting down randomly without prior warning.

-The laptop is not overheating.

-Fans are working properly.

-It's not a virus cos I have formatted the entire system thrice and installed Windows afresh, yet it still randomly shuts down.

-I have changed the SSD to another one, but it has been of no help.

-I have performed BIOS and Event log troubleshooting yet no error code.

-Used it without plugging to light, it still shuts down randomly.

-I used it plugged into the light, but it still shuts down randomly.

-Removed the battery and plugged it into the light directly yet it still shut down.

- It doesn't have shutdown timing, it can shut down after 5 minutes of putting it on or allow you more time.

The only notable that sometimes it shuts down when the fan starts blowing (tho the laptop is not hot).

-Thermal paste checked, ok.

-Taken to engineer but he couldn't figure out what's the fault.

-Even the seller is confused.

I ran a troubleshooting and system diagnostics and it all says the system is okay, drives are okay.

-The power key is set to sleep if pressed (so it's not a case of malfunctioning keyboard pressing itself).

-It only shuts down not tripped off, and has not restarted on its own before.

Engineers have run out of idea

Does anyone have any idea what could be the issue?

Am I Unlucky with my first time using Dell or it's common dell stuff?

The system is:

1terabyte ssd

32gram

4g dedicated Nvidia quadro

Windows 10

I have attached a video of how it typically shuts down. Thank you