I recently upgraded to a Gigabyte B550 motherboard after using an ASUS B450 without any issues. However, now my PC unexpectedly shuts down whenever I start downloading a game on Steam. This happens anywhere from one to five minutes into the download.
I suspect it might be a power supply issue, but everything is connected correctly, and my system recognizes all components. My power supply is known to work well and is rated at 550W, which should be enough for my setup. I've tried swapping RAM sticks, reseating all cables, and double-checking that my M.2 drive is fully connected, but I'm at a loss for what's causing this. Any insights or suggestions would be greatly appreciated!
3 Answers
Have you tried downloading something large outside of Steam? It might help to rule out a specific issue with the Steam client. Also, have you run any stress test software or played games? It could be something else entirely if it only fails during downloads.
Check your CPU temperatures; overheating could trigger shutdowns. A friend had a similar issue where the CPU was overheating and activating the shutdown protection, but if your temps are only reaching 40 degrees, that shouldn't be an issue here.
Yeah, I’m monitoring them during downloads and they’re staying below 40°C. Doesn’t seem to be the problem.
It sounds like your power supply might be at fault, especially if it shuts down under load. What brand and model is your PSU? Sometimes even good brands can have faulty units. You should also make sure that nothing is shorting out the board.
It’s the MSI MAG A650BN. Would that be a good unit, or should I try a different one?

I can’t think of any other big downloads right now. Any recommendations for something to try that’s over 8GB?