Black Screen

Try running the Apple Diagnostics.

Try an SMC reset and PRAM reset (hold the PRAM reset for at least three chimes or a full minute so it activates several times).

Run Disk Utility First Aid.

Run EtreCheck and post the report here using the "Additional Text" icon which looks like a piece of paper. If you allow EtreCheck "Full Disk Access" the summaries of the most recent logs will be included in the report.

Edit: I highly recommend you backup your laptop if you haven't done so already.

I suspect your SSD is failing. The false positive result you are referring was from the use of the older Apple Hardware Test and usually only occurred when the tests were looped according to an archived Apple article.

Run DriveDX and post the complete report here using the "Additional Text" icon. See if you can use DriveDX to run the SSD's internal selftest (not all Apple SSDs support these features).

Click on the "Additional Text" icon shown by the red arrow in this picture. It will allow you to submit the complete EtreCheck report. Use the "Share" and "copy" feature within EtreCheck so you can add the report to the Additional Text box.

Pro_stage wrote:

It does not matter whether I use the Intel GPU or the GeForce GPU; problem stays the same.

In the mean time I had also twice the issue that the keyboard and trackpad did not react anymore. Only the On/Off button was still working.

Not surprising since it wasn't behaving in the way I would expect for a GPU failure.

Q: do tasks like printing write to the HD, or is this all done in RAM?

Q: does OSX always use virtual RAM on the SSD, even if there is only one simple application running which would never need the installed 8GB RAM?

I'm not sure how macOS uses or handles virtual RAM with newer versions of macOS. I do know that on older versions of macOS that swap would not be used unless absolutely necessary.

Q: is it possible that the OS has lost some data? Can I restore the OS from the Backup (only OS, not the complete disk)?

Yes a system file could be damaged or corrupted. You can boot into Recovery Mode using Command + R to reinstall macOS over top of itself. As long as you do not erase the drive or volume, then it should not affect your data or user accounts.

Thanks for those reports. I don't see any concerns regarding the SSD from the DriveDX report. However, the EtreCheck report shows the one Kernel Panic being GPU related. Unfortunately the other Kernel Panics don't show any information. If the GPU is beginning to fail you could try using gfxCardStatus to force the laptop to use the Intel GPU instead.

https://github.com/steveschow/gfxCardStatus/releases/tag/v2.4.4i

To attempt to prevent a GPU issue you need to have gfxCardStatus set for the Intel GPU since the NVidia GeForce GPU is the one with the potential fault.

Contributors on these forums do not recommend using any cleaning apps since they usually cause more problems than they solve. Please do not install "CleanMyMac" as that app is known to cause all types of problems. This forum is full of user issues directly related to CMM. The best way to remove apps is to follow the developer's instructions. If you want to clean up the residuals from the apps already removed, then you can also use the EtreCheck report to guide you to the location of the files still needing to be removed from the "EtreCheck Clean Up" section.

As far as the Adobe Synchronizer that was most likely installed by one of your Adobe apps.