Many power cables and data cables exist inside your computer, providing power to various components and allowing communication between devices.The motherboard has one or more power connectors, as do devices like hard drives, optical drives, and even some video cards. All of these devices connect to the motherboard via the use of data interface cables (usually IDE cables).
Tip: You can see how all of these devices connect to one another by taking a Tour Inside Your PC.
Before you can reseat any internal data or power cable, you must power down the computer and open the case.
For detailed steps on opening your computer's case, see How to Open a Standard Screw Secured Computer Case. For screwless cases, look for buttons or levers on the sides or rear of the computer that are used to release the case.
If you're still having difficulties, please reference your computer or case manual to determine how to open the case. You can also get help at the PC Support forum.
Note: These photos accompanying the steps in this guide show how to reseat the power and data cables on a hard drive only. However, the logic is the same with the other cables and connections inside your computer.