An Ethernet cable is the wire that connects your personal computer either to the modem or to other computers in a network set up. It ends in a wide plastic connector with a clip that holds it in place in the port it is plugged into. This cable carries the signals to and from PCs and modems and is an essential part of a wired Internet connection.
1. Shut everything down. Before you attempt to investigate or try any method of removing the jammed cable, it is safer to first turn off the PC and modem and unplug their power from the wall socket. Wait for a minute or two for any residual electricity to disperse. Although the cable is insulated in rubber and the connector is plastic, PC casings are usually metal and you don't want to run the risk of getting shocked. It would also help to ground yourself by touching a different metal object such as a doorknob before you start tinkering with cable and the port which is usually located behind the desktop PC where all the other cables connect to.
2. Identify the problem. Possible causes for the jam could be that the clip on the connector is broken and may have lodged into the port; the connector itself is damaged; the port itself is misshapen by damage or the cable was forcibly plugged into the wrong port. One way to investigate the problem is to gently pull at the cable while wiggling it from side to side or top to bottom. By closely observing the connector and port you might be able to see and figure out what caused it to stick up. If the problem is not too serious, this method would usually pull the Ethernet cable free. The important thing to remember here is to pull gently. You don't want to damage the cable or the port by strongly tugging at the whole thing.
3. Use a screwdriver. The screwdriver must be a flathead and should be no wider than the Ethernet cable's connector. Carefully insert a small part of the flathead tip into the port under the connector end. 'Under the connector' refers to the other side of the connector opposite the clip. Apply small amounts of pressure to pry the connector loose while simultaneously pulling at the cable. You can also insert the flathead tip on the other sides of the connector as long as it's not on the side where the clip is attached as this could damage or further break the clip. Again it is important to not use excessive force.
The wide plastic connector end of an Ethernet cable fits only into a specific port whether on a PC, laptop or modem. Jamming is a rare occurrence but it does happen. If your attempts to take it out fail, you can always bring the whole thing to a computer shop. The repair will cost a little money but hopefully it won't be as much as the price you'll have to pay if you wreck the port and consequently need to replace it.