What is PSU-POWER-SAG-FREEZE?
Power Sag System Freeze / Lockup ranks as a high-severity power supply unit (PSU) issue in our database. The power supply unit voltage rails drop below the minimum safety threshold under sudden current transitions (transient power spikes), causing the CPU or GPU to freeze instantly without a Blue Screen. Follow the steps below to fix it.
Common Causes
- Degraded power supply capacitors
- High GPU transient spikes (e.g. RTX 30/40 series spikes)
- Loose ATX power connectors
Step-by-Step Fix Guide
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1
Ensure separate dedicated PCIe power cables are plugged into the GPU
Running dedicated cables prevents high current drops across a single 12V rail path.
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2
Replace the power supply unit with a high-quality unit containing robust capacitors
PSU replacement is eventually required if output capacitors have degraded.
Commands & Diagnostics
No specific commands required for this error. Follow the step-by-step guide above.
Frequently Asked Questions
The leading cause of PSU-POWER-SAG-FREEZE is degraded power supply capacitors, though high GPU transient spikes (e.g. RTX 30/40 series spikes) and loose ATX power connectors also show up in our reports.
Try "Ensure separate dedicated PCIe power cables are plugged into the GPU" first — it resolves most PSU-POWER-SAG-FREEZE cases on its own. Only work through the rest of the guide above if it comes back.
Rated high severity — PSU-POWER-SAG-FREEZE isn't immediately destructive, but recurring instances are a sign to fix it sooner rather than later.
Usually. PSU-POWER-SAG-FREEZE is fixable with the steps above; a full Windows reinstall is rarely necessary unless everything else has failed.
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