home networking - Why is my cat5e cable not okay?

My LAN cable seems to work (indicator LED lights up) but the computer can't find a connection. What's wrong?

Setup:

1. I had to run a network cable from a router in one room to a computer to another room, through a hole in the wall that was too small to pass the RJ-45 plug through. The plug was cut off and the cable passed through the wall.


2. Then a new plug was crimped on using this detailed explanation.


3. The connection didn't work because the (factory-made!) plug in the other end used a non-standard wire order.


4. I crimped a new plug on again, using the exact same order of the factory-made plug.


5. The LED indicators*) lights up on both ends, but the computer cannot find a connection.

*)
Router only has 1 green indicator: ON means OK.
Computer has the usual 2 LEDs: 1 green (solid=link?) and 1 orange (blink=collision?).

What can be wrong? How can I find out?

I don't have a cable tester. By visually inspecting my new plug, I think it's good; the wire order matches the other end, and all wires are all the way inside the plug and reach the connector piece. I've used the cable before (with both factory-made ends) so i don't think that the cable itself has a defect.

Answer

There must definitely be a problem with the cable, somewhere. Throw out the cable (don't know what part of the cable can be trusted) and get a new one, then carefully crimp both ends. And get a cable tester to check it.