Identify the startup stage
Record lights, fan activity, beep patterns and any display message. No power, no picture and failure to load the operating system are different problems; do not order a power supply from that description alone.
Check external connections safely
If there is no damage or electrical smell, check outlet, power lead and monitor input. Follow the component manuals. Never open a power supply or reuse modular power cables from a different model without explicit compatibility.
Review recent changes
Note any new component, cable, firmware setting or moved case. Internal connection checks require powered-off, model-appropriate procedures. A spinning fan does not prove the processor, memory and graphics path work.
Protect files before recovery
Confirm backups and encryption-key access before resets or reinstalling. Give support the exact parts and symptoms. Diagnosis and repair time depend on the cause, not a universal quick-fix promise.
Questions about this guide
What should I check before opening a gaming PC that has no power?
Check the external power connection and note any lights or sounds. Avoid opening the power supply, and stop if there is an electrical smell or visible damage.
What information helps after a new build fails to start?
Provide the full component list and describe what happens when power is pressed. Note recent assembly changes and diagnostic lights rather than assuming one part is defective.