I bought this open-box gaming PC about a week ago for 2,300 Canadian dollars. It has an RTX 5070, 32GB of RAM, and 1TB of storage. At first it worked perfectly, but now it randomly powers off or starts acting strangely shortly after I boot it up and launch a game—even relatively lightweight games. The shutdown only seems to happen when starting a game soon after turning on the PC. I also added an external 2TB SATA drive and initially suspected it, but removing it didn't solve the problem. What should I check, and should I return the system?
4 Answers
Start the return process through the store where you bought it. Random power-offs under gaming load could come from the PSU, overheating, the motherboard, or a graphics-card fault, and diagnosing all of that on a recently purchased machine isn’t really your responsibility.
Find the exact model and full specifications first, especially the power supply wattage and model. An RTX 5070 system needs a suitable, reliable PSU, and an undersized or faulty power supply can cause an immediate shutdown when the graphics card suddenly draws more power. You can run msinfo32 to identify the system model, then check the PSU label if the case is accessible.
If the seller allows troubleshooting, test individual components with a reputable utility such as AIDA64 and monitor CPU and GPU temperatures while launching a game. Also check whether the graphics drivers and BIOS are current. However, don’t spend too long stress-testing an open-box PC—if it keeps shutting off, returning it is the safer option.
Since the computer is only a week old and was sold as an open-box system, I’d contact the seller or manufacturer and arrange a return or repair rather than trying to fix a potentially defective machine yourself. Keep records of the shutdowns and explain that it powers off when a game starts.

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