Quick Answer

A full shutdown on an RTX 5070 build is a power or thermal protection trip, not a GPU defect. Confirm a quality 650W supply (Corsair RM750e or MSI MAG A750GL), reseat the power connector, and check Event Viewer for Kernel-Power 41. Heat above 88C or an under-spec PSU is the usual trigger.

Read the logs before you swap anything

Open Event Viewer (Windows Logs then System) and look for Kernel-Power 41 (a dirty restart), WHEA-Logger 18 and 19 (a hardware error), and Display TDR 4101 (a driver timeout). Sort by the timestamp of the last fault so you compare like with like. In HWiNFO64, log a five-minute gaming run and check whether the sudden shutdowns you see coincide with a temperature spike, a clock drop, or a voltage dip. A reboot or freeze wipes the screen evidence, so the log is the only honest record of what actually happened.

The fix sequence that actually works

Run DDU in Safe Mode, then reinstall a clean NVIDIA 57x.xx Game Ready driver. In the motherboard firmware, enable Resizable BAR and confirm the card sits in the top PCIe 5.0 x16 slot. Confirm a 650W-class power supply such as a Corsair RM750e or MSI MAG A750GL, and reseat the power connector fully. Watch temperatures: idle should sit around 36-45C, sustained load around 65-75C, and throttling kicks in near 88C.

Where SA buyers usually go wrong

Most call-outs we see locally are not faulty parts at all. Dust build-up from a dry Highveld winter, a cheap unbranded cable, a half-seated power connector, or a stale driver after a feature update cover the bulk of them. Before you budget for a replacement, work the free fixes first: a clean driver pass, a CMOS reset, a dust-out, and a known-good cable cost nothing. If a part genuinely is faulty, every component sold through Evetech carries a local warranty, so you log the RMA here rather than chasing an overseas seller. A quality power supply is the cheapest insurance: a 650W unit from around R1,500 protects a build worth far more.

FAQ

Why does my PC shut down completely under load?

A full power-off is a protection trip, usually heat above 88C or a power supply that cannot hold the spike. Confirm a quality 650W unit (Corsair RM750e or MSI MAG A750GL) and check Event Viewer for Kernel-Power 41.

Could the power supply be too small?

Yes, that is common after a GPU upgrade. Modern cards spike well above their rated draw, so an under-spec or ageing supply trips off. A 650W-class unit gives the headroom these spikes need.

Is heat or power more likely the cause?

Log both. If temperature hits the ceiling just before the shutdown, it is thermal; if it cuts out instantly with temps still fine, it is the power supply or a loose connector tripping protection.

Fix the cause, not the symptom. Before you shop for parts, run DDU and reinstall a clean NVIDIA 57x.xx Game Ready driver on a clean session, then re-test on one repeatable scene. If a part is genuinely faulty, log the local warranty through Evetech rather than guessing.