If you have gone through the steps above and are still unsure, the only definitive way to check a PSU is to swap it out.
If you are troubleshooting or planning an upgrade, the first step is to identify what power supply is currently inside your case. Software cannot usually detect the specific model of a PSU, so you must look physically. how to check power supply on pc
| Wire Color | Pin(s) | Expected Voltage | Tolerance | |------------|--------|------------------|-----------| | Orange | 1, 2, 12, 13 | +3.3V | ±5% | | Red | 4, 6, 19, 20 | +5V | ±5% | | Yellow | 10, 11 | +12V | ±5% | | Purple | 9 (standby) | +5VSB | ±5% | | Green | 16 (PS_ON) | ~0V when on, ~5V when off | - | | Grey | 8 (PWR_OK) | +5V (good) | - | If you have gone through the steps above
If any reading falls outside the safe tolerances, replace the PSU immediately. Step 5: Check Voltages via BIOS / UEFI | Wire Color | Pin(s) | Expected Voltage
Plug the 24-pin, 8-pin CPU, and PCIe cables directly into the tester. Power Up: Turn on the PSU switch.