I'm troubleshooting a desktop with a Radeon RX 5700 XT 8GB, Ryzen 5 3600, 16GB DDR4-3200, a SOYO B450M motherboard, and an Acer eMachines AC650 650W modular power supply running Windows 11 Pro. The monitor randomly loses signal while the case fans and the rest of the system remain powered on. Sometimes the GPU fans stop, but other times they continue spinning normally. After one incident, Windows started at 640×480, and Device Manager initially reported that the graphics device or driver could not start. Re-enabling it a second time restored normal operation. GPU temperature was around 66°C beforehand, so overheating doesn't seem obvious. I've reseated the card and its power connectors, checked the monitor and cable, tried the graphics-driver reset shortcut, restarted the PC, and reset AMD Adrenalin settings. The card uses one 8-pin and one 6-pin PCIe connector. Before replacing the GPU, what tests should I run to determine whether the problem is the graphics card, power supply, drivers, PCIe slot, or motherboard?
2 Answers
The power supply is a strong suspect, especially because the system loses graphics output while remaining powered on. A 650W rating is sufficient on paper, but the quality, age, and stability of this particular unit matter more than the wattage. If possible, borrow a known-good, reputable PSU with the required PCIe connectors and test the system under the same conditions. That is safer than buying a new graphics card first.
Also check the software and power-management side: reinstall the AMD driver cleanly, update the motherboard BIOS and chipset drivers if available, and test with a different DisplayPort or HDMI cable and output. Make sure Windows or the monitor isn’t entering a sleep or signal-saving mode unexpectedly. Since the problem has already produced a low-resolution fallback and a device-start error, a driver crash or hardware reset is more likely than a simple monitor sleep setting.
I checked the sleep-related settings and they aren’t enabled, so I’ll focus on a clean driver installation and testing another cable or output.
Do you think the PSU is likely enough to test first? I’m trying to avoid buying hardware unless I can narrow down the cause.