My laptop goes out permanently for a few seconds, several times in a row?

As I said in my question, my laptop keeps going off and on every time I use it. It's always a second that the screen goes black, but then several times in a row. Sometimes it's only twice, just 8 times. And the icons on my desktop are rearranged all the time, which is super annoying and my programs suddenly look a little different?
A few information on the side: It is probably not a virus, I regularly run virus tests, so far nothing has been found.
In addition: My laptop is already quite old (I think from 2012) and has already been resetted many times, but is currently working properly (apart from my black-out problem) because a new ssd hard disk was installed last year.
Could it be because the hard drive is new and the rest of the laptop is so old?
In any case, I'm extremely annoyed and would be happy if someone can help me there!

I guess that after these shutdowns, your icons are larger or automatically (instead of the so-called "grid").
Am I correct?

Yes exactly!

Do you happen to know that from older monitors that when you unplug them and plug them in again, the resolution is different?

Along with this, symbols and files are adapted to that resolution.

So let's assume the following for your laptop:

Your laptop has two "feet" on which your screen is connected to the computer itself.
Now imagine that the ultra-fine cables that run through these feet from the laptop's graphics card to the monitor are broken (because the laptop has been opened and closed for years).
There's a loose connection, which establishes / disconnects / induces / interrupts / etc.

So every time the graphics card has to "reorient" which resolution it should use.

Try to re-enact this thesis by me by opening the laptop when it is switched off (NOT STANDBY MODE!), Turning it on and when it is up, simply moving the monitor forwards and backwards.

If the monitor's dropouts become more, this is an indication of loose contact. (New purchase of a laptop advisable)

If this does not improve, it may be due to the graphics card driver that would have to be uninstalled and reinstalled later.

If that doesn't help you either, there's a risk that your graphics card will gradually give up.

8 years for a laptop is quite a lot.

Thanks for the answer! I just moved it and then it actually went out again: "D Oh man, but if that's really because of it, at least now I have an answer.