I got a used PC from a friend, it works perfectly fine most of the time. But some games crash unregularly but reproducibly. When a crash occurs sometimes my screen just goes blank, other times I get a popup from the AMD driver saying "AMD software detected that a driver timeout has occured on your system."

Here are the specs:
Graphics: MSI Radeon RX 5700 XT (driver version: 23.12.1, but I also tried several earlier versions)
Processor: AMD Ryzen 7 3800X 8-Core
Mainboard: Asus Prime X570-P
RAM: Corsair Vengeance LPX, 2x8GB
OS: Win10

Some games crash more than others, for example:
GrimDawn crashes after a few minutes. TitanQuest runs for at least an hour.
Pathfinder Wrath of the Righteous (and Kingmaker) crashes after a few hours.
Turbo Overkill crashed once (9 hours playtime so far).
Neverwinter Nights 2 crashes almost immediatly if it isn't the first game I play after a reboot.
Stellaris minimizes and I get the usual driver popup but continues to run fine afterwards (solid coding I guess).
A lot of other games sometimes crash. But there are a also games that never crashed for me including: Deep Rock Galactic, Factorio, Redout and Tyranny.
Older games tend to crash less than newer games, other than that I didn't really find a pattern in what games crash and which games run fine.

My friend says he never noticed any crashed, and given how some games are fine and how long even affected games can run before crashing I believe him.

I suspect the graphics card has some kind of fault, but is there any way I can verify that before I get a replacement? I already tried several GPU benchmarks, all ran through without a crash.