All models of the PlayStation 3 video game console have an ethernet port so you can choose to hook the system to the Internet with a cable connection. If a PS3 is experiencing difficulty connecting to the Internet with a variety of cables, there is a chance its ethernet port is damaged and needs to be replaced. The ethernet port is more difficult to replace than most other parts of the PS3 because it is attached to the motherboard and has to be soldered off. Only someone who has knowledge of what the ethernet port looks like and how to attach one to a motherboard should attempt this.
Disconnect the PS3 from the main electrical supply.
Bring the PS3 to a large clean area where you will take it apart and lay out its various components and pieces. Do not place the PS3 on a carpet or rug because the static can damage the circuitry.
Lay the PS3 down so it is horizontal and look at its left side. There is a rubber foot near the top-middle of this side. On some models, it is hidden under a warranty sticker. Carefully remove this foot using the small flathead screwdriver.
Remove the screw underneath the rubber foot using the T10 Torx screwdriver. Place it somewhere it won't roll away and don't forget where it came from in the system.
Slide the top of the PS3 case to the left. It may require a bit of force to slide if you are opening the console for the first time. After the top slides as far as it will go, lift the top and it should come off. Underneath is another cover.
Find the seven long screws holding the second cover in place and remove them using the Phillips head screwdriver.
Feel around the edge of the PS3 cover. There may be one to three clips holding it in place. If there are, very gently pry the clips loose using the flathead screwdriver.
Lift off the top of the cover carefully, because there may be wires attached to it. If there are, unplug these wires.
Remove all of the PS3 components by unscrewing them and unplugging them from the motherboard. It is easiest if you start with the power supply. The power supply is a large silver box on the left side of the PS3. From there, proceed to remove the Bluetooth device, the Blu-ray drive, and the small circuit board containing the "Reset" and "Eject" buttons.
Unscrew the motherboard from the case and take off the plastic cover with the HDD sticker on it. Lift the motherboard out of the case and set the case aside.
Remove the motherboard from its metallic casing. First remove the series of screws and brackets holding it to the casing. Then very gently pull up on the heatsink. The heatsink is attached to the CPU and GPU by thermal paste. Applying too much force may cause damage to the CPU or GPU. Do not touch the white thermal paste. It helps keep the system cool.
Lift the metal casing off of the motherboard. Be gentle because the metal is very thin and easy to bend.
Find and remove the old ethernet port with a soldering iron. Connect the new ethernet port onto the motherboard and port in the same position as the old port.
Reassemble the PS3 components in the reverse order that they were removed and reattach both covers to the PS3.
Most PS3 systems have a year-long warranty. If the warranty on your system is not yet up, consider sending in the PS3 instead of fixing it yourself. Sending a PS3 to Sony for them to replace the ethernet port is easier and safer, but it takes longer and may cost money for shipping. Taking apart the PS3 provides a great opportunity to rid it of any dust that's accumulated inside the system. Use canned air to blow the dust off the various parts. You can also use a vacuum very carefully. Do not touch the vacuum directly to the motherboard or any other circuitry.
Breaking the warranty seal on the PS3 ends the warranty, even if the warranty period is not yet over.