To remove and replace the old motherboard, remove the cables from the motherboard that attach to the case LEDs and buttons. Make notes in your journal to know where and how everything is connected before you start the upgrade.
Note how the motherboard secures to the case. Some mounting screws provide support, and some may provide an important grounding connection between the motherboard and chassis. In particular, pay attention to screws and standoffs that are non-metallic, because these may be insulators. Replacing insulating screws and supports with metal hardware that conducts electricity might damage electrical components.
Before installing the new motherboard into the computer case, examine the I/O shield located at the back of the computer case. Replace the old I/O shield if the new motherboard has different I/O ports or if the ports are in different locations.
Make sure that you use the correct screws. Do not swap threaded screws with self-tapping metal screws, because they will damage the threaded screw holes and might not be secure. Make sure that the threaded screws are the correct length and have the same number of threads per inch. If the thread is correct, they fit easily. If you force a screw to fit, you can damage the threaded hole, and it will not hold the motherboard securely. Using the wrong screw can also produce metal shavings that can cause short circuits.
Next, connect the power supply cables. If the ATX power connectors are not the same size (some have more pins than others), you might need to use an adapter. Connect the cables for the case LEDs and buttons. Refer to the motherboard documentation for the layout of these connections.
After the new motherboard is in place and the cables are connected, install and secure the expansion cards.
It is now time to check your work. Make sure that there are no loose parts or leftover wires. Connect the keyboard, mouse, monitor, and power. If a problem is detected, shut the power supply off immediately.
The firmware encoded in the motherboard CMOS chip might need to be updated so that the motherboard can support newer hardware. Updating the firmware can be risky. Before updating motherboard firmware, record the manufacturer of the BIOS and the motherboard and the motherboard model. You need this information when you go to the motherboard manufacturer’s site to get the correct installation software and BIOS firmware. Only update the firmware if there are problems with the system hardware or to add functionality to the system.