r/pchelp•1 mo. ago

ihaveaprobleminmypc

Dell OptiPlex 390 randomly power-cycles/boot-loops — BIOS works but PC shuts off, diagnostic LEDs 1-2-4 → 3. What should I test?

HARDWARE

Dell OptiPlex 390 randomly power-cycles/boot-loops — BIOS works but PC shuts off, diagnostic LEDs 1-2-4 → 3. What should I test?

Posted Sep 6, 2026, 3:26 AM UTC

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