The motherboard allows you to connect to the PC system all of the devices, such as the power supply and hard drive, required to run the computer. To replace a defective motherboard or upgrade to a new model, you must disconnect all of the cables connected to the motherboard and to the other devices installed to the interior of the PC.
Shut down the computer. Unplug all of the cables connected to the I/O (Input/Output) panel located on the rear of the computer.
Loosen any screws on the back of the computer case. Slide the cover panels away from the case. Touch the edge of the case to discharge any static electricity.
Disconnect the ribbon cable or SATA data cable connected to the hard drive and the IDE or SATA slots. Use a pair of forceps to disconnect the three-pin cable labelled "System Fan" or "SYS FAN".
Remove the plug labelled "CPU FAN," using the forceps. The connection is located next to the processor fan. Remove the 20-pin or 24-pin cable leading from the power supply to the motherboard.
Disconnect the SATA data cable or ribbon cable connected to the rear of the DVD drive. Disconnect the same cables from the appropriate slots on the motherboard.
Extract the cable connecting the memory card reader to the motherboard. Remove any cables connected to the expansion cards. Detach the wires connected to the power button and HDD and LED lights.
Shine a flashlight into the case to confirm you have removed all of the cables connected to the motherboard.
If you have more than one disc drive or hard drive installed to your computer, you will need to disconnect the cables for those devices as well. Do not pull on a connector's wires to remove it from the motherboard.