I recently built a PC with a Ryzen 7 5800 XT, Radeon 9060 XT, Thermalright AXP120-X67 cooler, ROG Loki 750W power supply, and an Asus Prime B550M-A WiFi II motherboard. It runs SteamOS on the beta preview channel, but the system restarts randomly every 10–20 minutes. This happens in both gaming and desktop mode, whether I'm playing a game or simply browsing.
Temperatures appear normal: roughly 45°C at idle and up to 70°C during gaming. I've already disabled HDMI Deep Color to limit the display to HDMI 2.0 at 60 Hz without VRR, enabled AMD Typical Current Idle, forced PCIe Gen 3 in the BIOS, disabled PCIe Link State Power Management in GRUB, and disabled Global C-States. MemTest86 completed four passes without detecting memory errors.
The build is brand new, so I'm unsure whether this could still be related to cooling or another hardware issue. What should I check next?
3 Answers
Since the system is restarting even while idle, don’t focus only on gaming temperatures. Check motherboard and GPU hotspot readings if available, confirm the PSU and power cables are firmly connected, and compare the behavior on a stable SteamOS release rather than the beta channel. A clean shutdown or kernel log around the restart may also help distinguish a power or hardware fault from a software issue.
Dust is unlikely with a new system, but checking the complete cooling setup is still a good first step. Look for blocked airflow, a loose cooler, poor contact, or any fan that stops under load. Normal reported temperatures don’t completely rule out a thermal problem, since not every component has a reliable sensor.
It’s worth checking for overheating-related shutdowns, even if the CPU and GPU temperatures look normal. Some critical components, such as motherboard VRMs, GPU hotspot areas, or other power circuitry, may not be included in the temperatures you’re monitoring. Make sure all fans are spinning properly and that the cooler and thermal interface are installed correctly.

This is a brand-new build, and the relatively low CPU temperatures make me think the cooler and paste are installed correctly. I’ll still inspect the cooling and consider reapplying the thermal paste if nothing else turns up.