Windows 10: My pc shut off randomly with or withour stress and give me black screen

Hi so my issue is i bought a gaming pc about 5 months ago .. the pc keep crashing at random times idk why like sometimes i use for 16 hours nothing happens and sometimes under hour at crashes a coulple times what's bothering me there no specific situation that always happens so i can catch the problem is so random .. i tested the rams they are okay and tested the gpu also its okay so idk if its the cpu but all the temps are okay i tried cinebench its not overheating or something i saw a youtuber who had the same issue the source of the video is : How I FIXED m

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PC randomly shuts down or gets black screen

I've been having this issue for a while, my PC will either randomly shut off usually when I'm playing games, I sometime get a black screen on both my monitors that doesn't allow me to press any button to do anything, this sometimes happens after my PC
randomly shuts down when I log in or when I'm playing a game, I know it's not a overheating issue.

 

New laptop hardlock with black screen

I have a new notebook, running Windows 10 Fall Creators Update, which is randomly freezing, showing a black screen. System specs:

• intel core i5
• HD is an SDD, 250GB
• GPU: Intel HD graphics 620

Symptoms:

• happens randomly, related to no particular reason, time of the day, and programs running
• when freezes, the notebook screen is "active" (back light is on) but completely black; external monitor, connected via HDMI, is black as well
• when freezes, no key input is responding. I tried to press "CAPS Lock", which has a led on it, and the led is not toggling
• I noticed I can keep the PC on for several days, without any problem. It always freezes whenever I'm actively using it

What I already tried:

• reinstall Windows from scratch (even starting from an external USB drive)
• run windows in "clean boot" mode (all non-MS services disabled, all startup programs disabled)
• update the BIOS, and all "relevant" drivers (GPU, System Firmware, network interface, bluetooth, ...) of the PC to the latest version
• testing the memory with MemTest86+: no issues, after several steps
• stressing the GPU with FurMark: reached quite an high temperature (70°), but no issues
• stressing the CPU with IntelBurnTest: reached quite an high temperature (70°), but no issues

Now, I would guess it's an hardware problem, but the strange thing is that we ordered 6 identical PCs, and this is happening on 4 of them. Therefore, for "statistical" reasons, we don't think it could be possible that all of them shows an HW issue... It only happens with a different rate from one PC to another (for instance, happens daily on my PC, and once a week on another)
Any idea on how to investigate this issue further?
Any test / improvement I can do?

 

Laptop randomly shuts down after latest Windows 10 update

Since the latest update of Windows 10 my computer decides to randomly shut down after every couple of minutes. First the screen goes black, then the sounds stops and after quite a while the power also goes down.

Obviously I though of cleaning the fan with a big vacuum, as suggested on My Windows 10 Computer Randomly Shuts Down . However, after doing this, the shutting down goes even quicker. I cannot even properly log-on before the shutdown takes place.

What should be my next step?

Ps. The computer is quited aged (roughly 3 - 4 years). The battery is dead enough such that I always need to have it plugged in an outlet. It might just be "done for" but I'm hoping to revive it for just a little bit more.