Really struggling with RJ45 connectors.

[HappyHippyDad]

I have fitted RJ45 connectors to either side of a piece of cat5 cable but when I test it on the laptop I get no ethernet connection. I also have a pre-made ethernet cable which works fine so I know it's my home made ethernet cable. I cut the cat5 to 12.5mm and connect both ends the same (i.e s68A)

I have practised this a few times now each with the same result, i.e. it doesn't work.

With a piece of twin and earth I could test for continuity at both ends but how do I test for continuity through an RJ45 connector?

The problems that I can see it as being are the following but I dont know which is the most likely or if there are other problems I missing?

1. Poor quality connectors, not actually making contact in the laptop or router.
2. cat 5 not actually terminated inside RJ45 connector
3. RJ45 Crimping tool not effective which leads to 2 above.

Cheers all.

 

[nate9595]

There are uses for a "mirror opposite" cable in networking with RJ45 connectors. I'm not sure this is one of those situations, though.

Agreed on the tester.

(Removed link - SC)

 

[DPG]

There are uses for a "mirror opposite" cable in networking with RJ45 connectors. I'm not sure this is one of those situations, though.

Agreed on the tester.


https://www.cablingstore.us/

No, it's not.

 

[UNG]

There are uses for a "mirror opposite" cable in networking with RJ45 connectors. I'm not sure this is one of those situations, though.

Can you explain?

 

[timhoward]

Can you explain?

I believe he was talking about making a cross-over cable to directly connect two devices. 1+2 to 3+6 and vice versa. Not needed so much these days!

 

[DPG]

I believe he was talking about making a cross-over cable to directly connect two devices. 1+2 to 3+6 and vice versa. Not needed so much these days!

Yes most devices auto sense the cable type now.

 

[SparkyChick]

Can you explain?

Back in the day, when switches and hubs weren't cheap, you could connect two PCs together using a crossover cable. If memory serves, you'd use the T568A standard on one end and T568B on the other so the cores in the connectors went something like this...

orange/white -> green/white
orange       -> green
green/white  -> orange/white
blue         -> blue
blue/white   -> blue/white
green        -> orange
brown/white  -> brown/white
brown        -> brown

These days you'd need to factor in the blue/brown pairs as well I think as for higher speeds I think they form a data path and you'd need to be careful with POE devices

 

[davesparks]

Can you explain?

I suspect the explanation is in the last line of that post, spam!

 

[UNG]

I believe he was talking about making a cross-over cable to directly connect two devices. 1+2 to 3+6 and vice versa. Not needed so much these days!

A crossover cable is not a "mirror opposite" though

 

[timhoward]

A crossover cable is not a "mirror opposite" though

I think @davesparks had it right - I didn't expand the message and see the website link.

 

[UNG]

Back in the day, when switches and hubs weren't cheap, you could connect two PCs together using a crossover cable. If memory serves, you'd use the T568A standard on one end and T568B on the other so the cores in the connectors went something like this...

orange/white -> green/white
orange       -> green
green/white  -> orange/white
blue         -> blue
blue/white   -> blue/white
green        -> orange
brown/white  -> brown/white
brown        -> brown

Crossover cables are still used today in some peer to peer applications although auto negotiation has somewhat reduced their use these days

These days you'd need to factor in the blue/brown pairs as well I think as for higher speeds I think they form a data path and you'd need to be careful with POE devices

This is the big minefield these days mixing POE and data does not normally end well

 

[UNG]

Oh... before I forget... don't bother making up patch cables if you need 'em. Just buy them in... it's cheaper, easier and looks better.

Some large patch frames I have worked on you had to make patch cables of the correct length and colour if you didn't want the head of I.T. to descend on you. On one site they had a patch cable trolley with all the different coloured cables and termination kit so you had no excuse

 

[SparkyChick]

Crossover cables are still used today in some peer to peer applications although auto negotiation has somewhat reduced their use these days

Totally, I just haven't made or used one in over a decade.

 

[timhoward]

Totally, I just haven't made or used one in over a decade.

Same. I have ruined a network tester by connecting it to an RJ45 socket which was in turn getting 55v on pins 4 and 5 from a telephone system though!