Hi,
I got a laptop [yoga-c740-15iml] of a friend I told I could fix the problem. The person didn't want to bring the laptop to a repair shop and even told me I could have the laptop for free if I can fix it.
But all my troubleshooting did not work out.
I did a fresh install of windows for starters -> still turns off. (Black screen, power led stays on for some time and at some point it goes out)
I started the Laptop from Linux -> same problem
I ran multiple memory tests and with a boot-usb stick (some "failed" because the system turned off, but I also managed to get a test that went through and I passed all tests with memtest86)
I used CrystalDiskMark to stress test the ssd with




