I've attached RJ45(https://www.kynix.com/Blog/The-Best-Tutorial-for-RJ45-Connector.html) connections to both ends of a cat5 cable, but there's no ethernet connection when I test it on my laptop. I also have a working pre-made ethernet cable, so I know it's my homemade ethernet cable. I cut the cat5 to 12.5mm and connect both ends with the same type of connector (i.e s68A)
I've tried it a few times now with the same outcome, namely that it doesn't work.
I could test for continuity at both ends with a piece of twine and earth, but how do I test for continuity through an RJ45 connector?
The following are the issues that I notice, but I'm not sure which is the most likely or if there are any more that I'm overlooking.
1. Poor quality connectors, not actually making contact in the laptop or router.
2. cat 5 not actually terminated inside the RJ45 connector
3. RJ45 Crimping tool not effective which leads to 2 above.
Cheers, all.

flight,

I just made a custom data cable of cat5 terminated with RJ45s. It was the last task of hardware updates in the office at home. The reason for being last is because it can be a real pain in the butt to get right. There have been times in the past that things did not go so well but this time it went without a hitch. Well almost.

I used this tool:

https://www.homedepot.com/p/Gardner-Bender-RG11-RJ45-Modular-Plug-Crimper-GMC-20...

By no means it is the best tool out there but will do the job if one takes a bit different approach.

1. Do not follow the directions on the package. I found if the all in one cutting step is followed the tool will nick the jacket and solid copper strands. The nick on the copper can be so severe that the copper will sever with some flexing of the cable!

2. Don't think the crimping operation can be completed in one compression. I also found that it can miss the outer end contacts entirely!

A work around as follows created a good cable in one try.

1. Place the cable in the opposite end of the tool that is meant to cut the cable completely and square. Cut the cable. Then place the cut cable in the other end up to the blade used to just cut the cable. Squeeze the handles just enough to nick the outer jacket on both side with the set of cutters...do not press hard! Work the other jacket off by bending the cable from the nicks just made. Separate the pair of wires in the proper order making the wires flat and together to fit into the connector. If some trimming is needed to make all ends the same length now is the time to do it. Necessary unraveling the twisted wires can cause the wires to change lengths somewhat.

2. When ready insert the wires into the RJ45 termination pushing the wire ends all the way to the end of the RJ45 making sure all wires are in the right slot and given a good amount of pressure. Place the assembly into the crimping part of the tool while keeping forward pressure on the cable keeping it seated firmly into the RJ45. Some clicking should be heard as the handle is squeezed as far as it will go. Repeat this several times then pull out the assembly for inspection. Under good light make sure all the contacts are pressed in at the same distance. If all looks good, reinsert the the RJ45 into the tool and squeeze a few more times for good measure.

I also found if the compression is not done right that over years this can cause a problem of  loosing data connections. I have used this tool a couple of times recompressing old data cables to fix problems of this nature.

HTH

John