I upgraded my power supply and graphics card last night. The computer worked for a while, but the GPU hotspot reached about 104°C, so I planned to return it. While gaming today, the keyboard and mouse lighting suddenly turned off, the case fans stopped, and only the CPU fan kept spinning. I opened the case and heard an unusual noise from the power supply fan. Even after unplugging the computer, the noise continued for several minutes. I later noticed that the CPU power cable had somehow come loose and firmly reconnected it. I'm worried that something may have shorted or been damaged. What should I check before powering the system on again?
3 Answers
A 104°C GPU hotspot is high enough to investigate, but it may be caused by poor case airflow, an uneven cooler mount, or the card’s cooler design rather than a defective GPU alone. Check that the fans are spinning, improve intake and exhaust airflow, and compare the GPU core temperature with the hotspot temperature. The sudden shutdown itself is more likely related to the loose power connection or a PSU issue than the hotspot temperature by itself.
First, confirm the exact PSU model and make sure every connection is fully seated, especially the 8-pin CPU/EPS cable, motherboard power, GPU power, and front-panel connections. If the PSU is modular, use only the cables that came with that specific PSU—modular cables are not interchangeable between units. Check for burnt marks, melted plastic, a sharp electrical smell, or damaged pins before testing it again.
A loose CPU power cable can definitely cause an immediate shutdown, and it does not automatically mean the whole PC is dead. Disconnect power, reseat both ends of the cable if applicable, and verify the PSU switch and wall connection. If you hear buzzing, clicking, or grinding from the PSU again, or notice any burning smell, don’t keep powering it on—test with a known-good PSU or have the system inspected.
I checked the cables and found that the CPU power cable had come loose. I reconnected it firmly, but I’m still going to inspect everything for heat or damage before trying again.