When you troubleshoot issues with an internal power cable, there are some quick tests that you can complete to rule out potential problems. You can test to make sure that the following components are working correctly and are not the source of the issue:
To test your setup components, try the following:
Use the power supply, computer part, and power cable in another setup to see if the problem is with the components or the setup.
Use a different power supply, computer part, and power cable in your setup to see if the problem persists. Ideally, you should test a component that you know works in another setup.
When you test your cable, it is recommended that you do the following:
Make sure that the cable is firmly inserted into both ends.
The polarity (usually indicated by the color of the cables) matches.
No pins are bent or missing on the power supply cable or header, or the computer part.