My uncle built me a PC about a year ago, but I've been dealing with problems that make several games unusable. I see brief red and blue pixel flashes, fuzzy black-and-white artifacts that disappear when I move the camera, and occasional freezes followed by a complete game or system crash. Both monitors sometimes freeze or go black. Some games report errors such as "rendering device lost" or that the graphics device disconnected. I checked that the RTX 3060 appears to be properly seated, but the issue continues. Could this be a failing graphics card, a driver or power problem, or an incompatibility with the motherboard? The exact motherboard model is currently unknown.
3 Answers
A stress test passing does not completely rule out a hardware fault. Some problems only appear in particular games, during changing power states, or when a specific driver feature is used. You could also try setting the PCIe slot to an earlier supported generation in the BIOS, reseating the card and its power connector, and checking the system event logs. If the symptoms remain after a clean driver install, hardware testing at a repair shop is reasonable.
If your processor has integrated graphics, remove or disable the RTX 3060 temporarily and run the affected games using the motherboard video output. If the crashes and artifacts stop, that makes the GPU or its power connection much more suspicious. If there is no integrated graphics, testing another known-good graphics card is the most useful comparison.
The colored pixels, disappearing artifacts, black screens, and rendering-device errors point more toward a graphics card, driver, power-delivery, or overheating problem than a basic motherboard incompatibility. An RTX 3060 should work with a modern motherboard. Try a clean graphics-driver reinstall, check GPU temperatures and power cables, and test with another display cable or monitor if possible.

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