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Standard User DIY_Johnny
(newbie) Sat 19-Feb-11 21:31:35
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Shorted Cat6E Cable


[link to this post]
 
Hi all, happy to be here!
my first post so hope someone can help.

I have wired up flat with cat 6E cables. I have bought a network cable tester and found that there is a short between pins 4 &5 (blue cable and Blue with white bands) I confirmed with my multimeter that there is continuity between these two cables.

I am so annoyed with myself that I didn't test this earlier as now I have a wood floor down and not possible to take it up

My question is: do I need all 8 cables for an Ethernet connection, i.e. to connect my PC to a SKY modem for example

Running a new cable means surface mounting which really will look awful

Many thanks all
Moderator billford
(moderator) Sat 19-Feb-11 21:38:32
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Re: Shorted Cat6E Cable


[re: DIY_Johnny] [link to this post]
 
A fault in one of the conductors usually manifests as a break, it can take pretty hefty damage to cause a short circuit.

On the other hand, a fault in the termination at one end can easily result in a short circuit... I'm assuming you can get at the ends without major upheaval, give them a good examination.

Someone else will have to comment on how many pairs you need...

~~~~~~~~~~~~
Bill

bill@thinkbroadband.com ________________________Planes and Cars and ...________________________BQM
The author of the above post is a thinkbroadband moderator but it does not constitute an official statement on behalf of thinkbroadband.
Standard User huwwatkins
(regular) Sat 19-Feb-11 21:57:48
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Re: Shorted Cat6E Cable


[re: billford] [link to this post]
 
2 pairs for 10/100 , 4 for gigE


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Standard User DIY_Johnny
(newbie) Sat 19-Feb-11 22:02:45
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Re: Shorted Cat6E Cable


[re: billford] [link to this post]
 
Hello Bill, perhaps I am using the wrong terminology. I cut the RJ45 off both ends and tested one end with a multimeter with the continuity setting. When I place the 2 probes on the Blue & Blue /White cable it signals continuity so I guess there is a screw or the insulation is damaged under the floor

I attached 2 new RJ45 modular inserts and used the network tester. It shows that the pins 4&5 light at the same time, I assume this means the same thing. Further when I use the main part of the network tester (i.e. without the remote end attached) pin 5 lights intermittently

Thanks for your response by the way
Standard User DIY_Johnny
(newbie) Sat 19-Feb-11 22:14:30
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Re: Shorted Cat6E Cable


[re: huwwatkins] [link to this post]
 
Hello huwwatkins,
forgive my ignorance of this subjects but does that mean I only use 4 wires (2 pair) for up to 100mps data type. Would that include sky boxes, PC, live streaming of movies etc across the web?

If so, which pins should I use or does the device (such as a wireless network card) detect that automatically?
Standard User Rockh
(eat-sleep-adslguide) Sun 20-Feb-11 10:06:44
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Re: Shorted Cat6E Cable


[re: DIY_Johnny] [link to this post]
 
For 100 meg working you only use 2 off the 4 pairs, these are the orange and green pairs (pins 1, 2, 3 and 6). For Gig you use all 4 pairs.
Your network card will sort out the connection, however having a short across 4&5 may upset the kit, might be worth removing these wires at the terminals on the socket.

Dave
Standard User E7er
(knowledge is power) Mon 21-Feb-11 12:00:28
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Re: Shorted Cat6E Cable


[re: DIY_Johnny] [link to this post]
 
In reply to a post by DIY_Johnny:
Hi all, happy to be here!
my first post so hope someone can help.

I have wired up flat with cat 6E cables. I have bought a network cable tester and found that there is a short between pins 4 &5 (blue cable and Blue with white bands) I confirmed with my multimeter that there is continuity between these two cables.

I am so annoyed with myself that I didn't test this earlier as now I have a wood floor down and not possible to take it up

My question is: do I need all 8 cables for an Ethernet connection, i.e. to connect my PC to a SKY modem for example

Running a new cable means surface mounting which really will look awful

Many thanks all
Hi, it sounds complicated connecting up different colour wires…

http://www.duxcw.com/digest/Howto/network/cable/cabl...

Take Note
The importance of the word "twist" in making network cables which will work. You cannot use an flat-untwisted telephone cable for a network cable. Furthermore, you must use a pair of twisted wires to connect a set of transmitter pins to their corresponding receiver pins. You cannot use a wire from one pair and another wire from a different pair.

Note that pins 4, 5, 7, and 8 and the blue and brown pairs are not used. Quite contrary to what you may read elsewhere, these pins and wires are not used or required to implement 100BASE-TX duplexing--they are just plain wasted.

Orange (SMPF) LLU 20 Meg. Sync 11864 Kbps Downstream, 1157 Kbps Upstream.
3Com 3CRWDR101A-75 ADSL2/2+ router
Netgear DGN1000 ADSL2+ wireless N 150 Router supplied by Orange
BT Business Hub 2Wire 2700HGV v2 ADSL2+ Dual SSID wireless Router
Standard User DIY_Johnny
(newbie) Mon 21-Feb-11 19:13:03
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Re: Shorted Cat6E Cable


[re: E7er] [link to this post]
 
Hi E7er,

I guess its somewhat lucky in a way that I damaged one pair only, although I assume the colouring is for standardisation and you could have one pair going to one corresponding set of pins (e.g. 1&2 swapped with 3&6 at both ends)

I have a look at running a new cable and its really not possible without a lot of work trying to find a new route so I guess I will stick to the 100BASE-TX duplexing as you note.

Perhaps I may need it in the future, not sure, but I guess its still find for streaming blue ray movies and the like

Thanks for the link, very useful
Standard User DIY_Johnny
(newbie) Mon 21-Feb-11 19:14:12
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Re: Shorted Cat6E Cable


[re: Rockh] [link to this post]
 
Many thanks thanks Rockh
Anonymous
(Unregistered)Fri 14-Sep-12 23:06:25
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Re: Shorted Cat6E Cable


[re: billford] [link to this post]
 
You don't need all 4 pairs but you do need the blues so swap the blues for browns at both ends weather it's rj45 or rj jacks and you'll be golden.
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