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UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
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#41
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Network wiring problem - weird one!
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#42
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Network wiring problem - weird one!
On 18 Sep, 09:55, Adrian wrote:
gurgled happily, sounding much like they were saying: The only thing missing in this feast of information is how the individual pins are numbered on the socket. *I can find how they're numbered on the cable, but not the socket. A two-second google finds...http://pinouts.ru/connectors/rj45m.gif Ah, but that's the cable. I need the socket. Edward |
#43
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Network wiring problem - weird one!
Bob Mannix wrote:
One obvious answer is that you have patch leads with cross-overs in them. No, we've eliminated that one. His Netgear DG834 has autosensing ports that can cope with this. -- Mike Clarke |
#44
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Network wiring problem - weird one!
Andy Wade wrote:
John Rumm wrote: Yup, when working with signals that are sent as a differential pair, it is vital to make sure they are carried by a twisted pair. Just having the right pins joined together is not enough at these frequencies. It's also important to maintain the twisting of each pair right up as close as possible to the IDC terminals of the socket. The 'as installed' picture provided didn't show particularly good practice in this respect. Now can I ask a supplementary Ethernet question about switches while all the networking experts are around? Can you cascade the cheap unmanaged switches /ad-infinitum/ and maintain communication between all nodes? For example say two ports from a typical 4-port ADSL router, R, each feed remote 8-port switches, A & B. Each switch provides 7 ports used to connect local network devices. In this network will a device on switch A be able to communicate with a device on switch B, via the switch in R? Yes. Thats the great thing about switches. They reconstitute to digital, and then retransmit as analogue. You will get a delay through each one, which makes short packet traffic a bit slower though. |
#46
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Network wiring problem - weird one!
wrote:
Anyone any thoughts? Disconnect all patch leads. Connect the laptop directly to the router using one of the patch leads. Ping the router. If that passes then get another patch lead and connect that directly to the router and the laptop and ping the router. With luck you now have two patch leads that you know are OK. Patch one port on the router to the patch panel using one of the patch leads. Connect the laptop to the appropriate socket using the other patch lead. Ping the router. If that fails remove the faceplates and check wiring integrity. Call the ****wit who installed it and get him to fix it. |
#47
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Network wiring problem - weird one!
In article
, wrote: The only thing missing in this feast of information is how the individual pins are numbered on the socket. I can find how they're numbered on the cable, but not the socket. The URL I gave shows this. -- *Hard work pays off in the future. Laziness pays off now * Dave Plowman London SW To e-mail, change noise into sound. |
#48
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Network wiring problem - weird one!
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#49
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Network wiring problem - weird one!
On 17 Sep, 16:27, wrote:
[...] Many thanks to all of you who have tirelessly helped in the quest to allow my peri-teenage son to watch unsuitable YouTube videos in the privacy of his bedroom. I'm EXTREMELY happy to report that, thanks to your nuggets of information, there is one very red-faced network engineer swapping Green/White and Orange/White wires even as I speak. Job done. Thanks again Edward |
#51
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Network wiring problem - weird one!
wrote: The only thing missing in this feast of information is how the individual pins are numbered on the socket. *I can find how they're numbered on the cable, but not the socket. From Mike's picture. it looks more like phone cable than cat5e to me but that could be because all the twists have been undone - but they don't look tightly twisted back at the insulation cut - is it really Cat5e cable? I'm now sure the pairs are split onto the incorrect pins of the socket. I can see the "1" by the wh/gr and I can't work out how the opposite corner connector could be the other half of the pair. I suggest you get your friend back, asking him to do it properly and show him http://www.surrey.ac.uk/eng/Intranet...upport/UTP.HTM The wiring of the socket is at the top. (and you'd think someone at surrey.ac.uk would spell correctly...) Don't forget to check he cuts off the tiny piece of each wire at the end that was used in the punch-down connector, so he is connecting to a fresh piece of wire - and get him to fit a tie-wrap as a strain relief. -- John W To mail me replace the obvious with co.uk twice |
#52
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Network wiring problem - weird one!
"Andy Burns" wrote in message ... On 18/09/2008 09:38, dennis@home wrote: I dimension the UK for switched local access once and had it put to the board at BT. It was to give 100M access to every home The limiting factor in that case is more likely to be the size of the MAC address tables in the switches. Not the way it was designed. It still used IP and/or MPLS to route/switch between areas. You could get a nice 16+2 port switch chip that supported MPLS. The best thing was how everyone keeps telling me MPLS is a core protocol when it looks like it could be very useful at the edge to do things like switching different service types down different paths. Another idea I see being copied is the idea of having different physical ports dedicated to different services so that you don't have to delve into the protocols to set priorities e.g. you plug your BT (IP) phone into ports 1, video into port 2, ... , internet port 4, etc. each with a different plug. I never did like the idea that you needed to take a protocols apart to set priorities. |
#53
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Network wiring problem - weird one!
wrote in message ... The only thing missing in this feast of information is how the individual pins are numbered on the socket. I can find how they're numbered on the cable, but not the socket. The photo has pin numbers/colours on. I can't see them very well because of all the wires. You could post a pic of each end if they are different. |
#54
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Network wiring problem - weird one!
The Natural Philosopher coughed up some electrons that declared:
You should point him to that video somewhere of some bloody teenager masturbating in front of his computer, and tell him it will make him go blind, or give him a permanent squint... What video would that be :-| And how do you know about it? runs |
#55
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Network wiring problem - weird one!
On 18 Sep 2008 09:16:44 GMT, Adrian wrote:
holds head in hands D'you think that pin 1 on the cable might correspond to pin 1 on the socket...? You could assume that but it is not a safe assumption. BT type telephone connectors have arse about face numbering between the scoket and the plug. -- Cheers Dave. |
#56
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Network wiring problem - weird one!
"Dave Liquorice" wrote in message
ll.net... On Wed, 17 Sep 2008 20:02:56 +0100, Ron Lowe wrote: Pins 1+3 MUST be from one twisted pair ( usually orng / orng-wht, but could be any colour ). Pins 3+6 MUST be from another twisted pair. ( usually grn / grn-wht, but again, could be any colour. ) This is absolutely crucial. snip You just need to do what we say. snip I've installed these things more times than I can recount. You better recount your pin numbers, I'm intriged by the common use of pin 3 between two pairs. So on balance I think it's probably best if the OP does not "do what we say". B-) Looking at the picture of the socket back it does appear that the grn/wht and org/wht wires are transposed. Look at the colour coding blobs half hidden by the wires. It's normal to have adjacent terminals to be a pair not have them split apart. Having them apart plays havoc with the impedance an possibly the balance as well. -- Cheers Dave. Yes indeed, one typo, as has already been ack'd. Of course we don't use pin 3 twice over. My original post is correct, concerning what wires go where. R. |
#57
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Network wiring problem - weird one!
"Andy Wade" wrote in message
... John Rumm wrote: Yup, when working with signals that are sent as a differential pair, it is vital to make sure they are carried by a twisted pair. Just having the right pins joined together is not enough at these frequencies. It's also important to maintain the twisting of each pair right up as close as possible to the IDC terminals of the socket. The 'as installed' picture provided didn't show particularly good practice in this respect. Now can I ask a supplementary Ethernet question about switches while all the networking experts are around? Can you cascade the cheap unmanaged switches /ad-infinitum/ and maintain communication between all nodes? For example say two ports from a typical 4-port ADSL router, R, each feed remote 8-port switches, A & B. Each switch provides 7 ports used to connect local network devices. In this network will a device on switch A be able to communicate with a device on switch B, via the switch in R? -- Andy More or less. Try to maintain a 'tree' structure, and avoid any loops in the topology. ( ie there being 2 different routes between any 2 switches, for example running a cable from A to B in your example, when there's already a route via R ) Smarter switches will handle looped topology correctly, ( and indeed will use this for redundancy ) using the 'spanning tree protocol', but cheap switches will probably not, and this can result in odd behaviour where some packets accelerate in a clockwise direction, colliding with an anti-clockwise beam of packets. The resulting black hole will eat the server room. -- Ron |
#58
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Network wiring problem - weird one!
Ron Lowe wrote:
In addition to what the others have said ( incorrect patch cables ); can you unscrew the face-plates, and either take a picture or describe what wires have been punched down into which terminals? I'd expect it to be: 1 Orange / White 2 Solid Orange 3 Green / White 4 Solid Blue 5 Blue / White 6 Solid Green 7 Brown / White 8 Solid Brown Er, well then, you'd be wrong to expect that. The TIA 568B standard (almost universal for UK structured cabling installations) for an RJ45 connector is based upon the Western Electric Colour Code, as follows 1. White/Orange 2. Orange or Orange/White 3. White/Green 4. Blue or Blue/White 5. White/Blue 6. Green or Green/White 7. White/Brown 8. Brown or Brown/White In all cases where two colours are shown, the first colour is the main colour and the second colour is the tracer (or stripe) colour. http://en.wikipedia.org/wiki/TIA-568B |
#59
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Network wiring problem - weird one!
Smarter switches will handle looped topology correctly, ( and indeed will
use this for redundancy ) using the 'spanning tree protocol', What switches have that built in?..... -- Tony Sayer |
#60
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Network wiring problem - weird one!
"tony sayer" wrote in message
... Smarter switches will handle looped topology correctly, ( and indeed will use this for redundancy ) using the 'spanning tree protocol', What switches have that built in?..... -- Tony Sayer Certainly the cicso ones do. I can't really say about others. You'd need to check their data sheets. -- Ron |
#61
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Network wiring problem - weird one!
"Ron Lowe" ronATlowe-famlyDOTmeDOTukSPURIOUS coughed up some electrons
that declared: "tony sayer" wrote in message ... Smarter switches will handle looped topology correctly, ( and indeed will use this for redundancy ) using the 'spanning tree protocol', What switches have that built in?..... -- Tony Sayer Certainly the cicso ones do. I can't really say about others. You'd need to check their data sheets. And Extreme Networks (much underrated IMO - very nice to work with) Cheers Tim |
#62
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Network wiring problem - weird one!
On Thu, 18 Sep 2008 09:14:41 UTC, Mike Clarke
wrote: Bob Mannix wrote: One obvious answer is that you have patch leads with cross-overs in them. No, we've eliminated that one. His Netgear DG834 has autosensing ports that can cope with this. But does the PC at the other end of the circuit? -- The information contained in this post is copyright the poster, and specifically may not be published in, or used by http://www.diybanter.com |
#63
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Network wiring problem - weird one!
"Bob Eager" wrote in message ... On Thu, 18 Sep 2008 09:14:41 UTC, Mike Clarke wrote: Bob Mannix wrote: One obvious answer is that you have patch leads with cross-overs in them. No, we've eliminated that one. His Netgear DG834 has autosensing ports that can cope with this. But does the PC at the other end of the circuit? Only one end needs to. |
#64
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Network wiring problem - weird one!
Tim S wrote:
The Natural Philosopher coughed up some electrons that declared: You should point him to that video somewhere of some bloody teenager masturbating in front of his computer, and tell him it will make him go blind, or give him a permanent squint... What video would that be :-| And how do you know about it? I THINK someone posted it here as being representative of Dr Drivel, in his previous incarnation. runs |
#65
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Network wiring problem - weird one!
Dave Osborne wrote:
Ron Lowe wrote: In addition to what the others have said ( incorrect patch cables ); can you unscrew the face-plates, and either take a picture or describe what wires have been punched down into which terminals? I'd expect it to be: 1 Orange / White 2 Solid Orange 3 Green / White 4 Solid Blue 5 Blue / White 6 Solid Green 7 Brown / White 8 Solid Brown Er, well then, you'd be wrong to expect that. The TIA 568B standard (almost universal for UK structured cabling installations) for an RJ45 connector is based upon the Western Electric Colour Code, as follows 1. White/Orange 2. Orange or Orange/White 3. White/Green 4. Blue or Blue/White 5. White/Blue 6. Green or Green/White 7. White/Brown 8. Brown or Brown/White In all cases where two colours are shown, the first colour is the main colour and the second colour is the tracer (or stripe) colour. http://en.wikipedia.org/wiki/TIA-568B However the latter differs from the former only in the sense of colors. As far as the electricals go, it's pairs in the right pairs of terminals, so will work just as well. AS I said before' all that matters is a pair on 1 nd 2, a pair on 3 and 6, a pair on 4 and 5 and a pair on 7 and 8. Which way round they are, or what colors they use, are actually not a problem. In fact for ethernet up to 100Mbps,only 3 and 6, and 4 and 5 need be connected at all.. |
#66
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Network wiring problem - weird one!
On Thu, 18 Sep 2008 20:15:57 UTC, "dennis@home"
wrote: "Bob Eager" wrote in message ... On Thu, 18 Sep 2008 09:14:41 UTC, Mike Clarke wrote: Bob Mannix wrote: One obvious answer is that you have patch leads with cross-overs in them. No, we've eliminated that one. His Netgear DG834 has autosensing ports that can cope with this. But does the PC at the other end of the circuit? Only one end needs to. Ah...yes! -- The information contained in this post is copyright the poster, and specifically may not be published in, or used by http://www.diybanter.com |
#67
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Network wiring problem - weird one!
John Rumm wrote:
Yup, that would be fine. Thanks to all who replied on this. The next question then is when/where/why would you use a managed switch? -- Andy |
#68
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Network wiring problem - weird one!
Andy Wade wrote:
John Rumm wrote: Yup, that would be fine. Thanks to all who replied on this. The next question then is when/where/why would you use a managed switch? When you want more control that you get with an unmanged one. You can enforce better security (i.e. limiting traffic between certain parts of a network to only those parts, regardless of any tricks people may play to try to spoof the switch). You can actively manage traffic better - allocating more bandwidth to certain applications or reserving a certain quality of service. You usually get SNMP monitoring so you can check on the state and performance of attached kit. Posher ones will have support for virtual lans and things like spanning tree protocol. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#69
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Network wiring problem - weird one!
John Rumm wrote:
When you want more control that you get with an unmanged one. You can enforce better security (i.e. limiting traffic between certain parts of a network to only those parts, regardless of any tricks people may play to try to spoof the switch). You can actively manage traffic better - allocating more bandwidth to certain applications or reserving a certain quality of service. You usually get SNMP monitoring so you can check on the state and performance of attached kit. Posher ones will have support for virtual lans and things like spanning tree protocol. Noted - thanks. -- Andy |
#70
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Network wiring problem - weird one!
"The Natural Philosopher" wrote in message
... In fact for ethernet up to 100Mbps,only 3 and 6, and 4 and 5 need be connected at all.. Completely WRONG ( (copyright) TNP ) ITYM 1+2, and 3+6. How can you have managed all these years, getting it wrong every single time? :-) - Ron |
#71
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Network wiring problem - weird one!
Ron Lowe wrote:
"The Natural Philosopher" wrote in message ... In fact for ethernet up to 100Mbps,only 3 and 6, and 4 and 5 need be connected at all.. Completely WRONG ( (copyright) TNP ) ITYM 1+2, and 3+6. How can you have managed all these years, getting it wrong every single time? :-) Ah, you may be right..after the first time when I actually taught some people who did wiring how to do it, I employed them to do it every time. And promptly forgot 90%. - Ron |
#72
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Network wiring problem - weird one!
wrote:
The only thing missing in this feast of information is how the individual pins are numbered on the socket. I can find how they're numbered on the cable, but not the socket. With RJ45 the pin numbers on the socket match those of the plug (unlike say the BT phone plug!). However, that is not usually particularly useful information since the presentation of the IDC terminals will vary in layout depending on both brand and type of socket. So you need to follow the colour code on the particular socket. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#73
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Network wiring problem - weird one!
Dave Plowman (News) wrote:
In article , wrote: The only thing missing in this feast of information is how the individual pins are numbered on the socket. I can find how they're numbered on the cable, but not the socket. The URL I gave shows this. Another very good site for pinouts of just about everything: http://www.hardwarebook.info/ -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#74
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Network wiring problem - weird one!
In article ,
John Rumm wrote: Dave Plowman (News) wrote: In article , wrote: The only thing missing in this feast of information is how the individual pins are numbered on the socket. I can find how they're numbered on the cable, but not the socket. The URL I gave shows this. Another very good site for pinouts of just about everything: http://www.hardwarebook.info/ Excellent resource - thanks. -- *Money isn't everything, but it sure keeps the kids in touch. Dave Plowman London SW To e-mail, change noise into sound. |
#75
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Network wiring problem - weird one!
On Wed, 17 Sep 2008 16:49:50 +0100, Dave Plowman (News) wrote:
In article , wrote: When we had our extension built recently, I took the opportunity to install a Cat5 LAN. Well, to be more accurate, the electrician ran the cabling in but said he didn't do network wiring so the tails sat there for a while until eldest son got his new laptop. I got a friend who is an experienced network engineer with his crimping tool to install the face plates for the network points. A diagram of the network is he http://www.flickr.com/photos/30588773@N04/2864919945/ The engineer had a wee gizmo that he plugged into the individual points and then another into the 4-gang which lit up to show that the wires were correctly connected. Everything seemed fine and dandy and, as I say, he's an experienced engineer. Unfortunately the network doesn't work. A laptop plugged into any of the individual 1-gang outlets can't see the network. However, if it's plugged directly into the back of the router, all is fine. Anyone any thoughts? I bought the cable from work (we do network installations, though I'm a software engineer myself) - it's unshielded twisted pair, and it's what we have in our work LAN. Experienced engineer or not he's made a cock up? Here's the correct wiring:- http://www.jaysafe.co.uk/technical/rj45.asp Just a thought - have you got face plates either end with jumpers to the router? Looks like it from his diagram. As long as the colours each end of a cable and on both ends of the faceplates are the same it should 'work', although using the proper EIA/TIA 568 A or B colour coding will give you much better range and lower crosstalk figures. None of the cables in the system should be 'crossover' types, although the majority of routers now have MDI/MDIX ports that can automatically cope with straight or crossover anyway. If a network engineer did the faceplates and the cables came from work then both of those should be OK. That leaves the cables. Cat-5 is sturdy enough, but probably a bit lighter than your sparks was used to, especially since they are almost certainly solid core. Putting too tight bends or bending them too often could get you snapped cores. But again, you say the network tester said it was OK. (Aside: if anybody needs one, try this - it's simple but it works well and costs almost nothing: http://www.dealextreme.com/details.dx/sku.4439) So if all the wiring is OK, that leaves... nothing. With the laptop plugged into a faceplate, can you ping the routers IP address? Is the four way faceplate fully wired into the router, or do you just have a couple of cables? Are you sure the right sockets are connected all the way back to the router? When you plug the laptop in, does the 'link light' come on (usually a green led on the rj45 socket on the laptop, and another on the router?) |
#76
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Network wiring problem - weird one!
In article , urd3
@bitrot.co.uk says... Cat-5 is sturdy enough, but probably a bit lighter than your sparks was used to, especially since they are almost certainly solid core. Putting too tight bends or bending them too often could get you snapped cores. But again, you say the network tester said it was OK. (Aside: if anybody needs one, try this - it's simple but it works well and costs almost nothing: http://www.dealextreme.com/details.dx/sku.4439) So if all the wiring is OK, that leaves... nothing. Except for the problem already identified in this thread... That type of tester will only tell if you have random wires on the same pins at each end, not whether you have use the correct wires from the twisted pairs onto the correct socket pins. It indicats all is fine if the cable is basic muti-wire alarm cable instead of Cat5 The place I used to work was wired using Cat5. (As a foreigner by a local BT installer.) He had installed the pairs 1-2, 3-4, 5-6 & 7-8, which would have been fine on your tester. It worked until we started using 100Mbps and auto speed detect devices... -- John W To mail me replace the obvious with co.uk twice |
#77
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Network wiring problem - weird one!
On Sat, 20 Sep 2008 09:43:29 GMT, PCPaul wrote:
(Aside: if anybody needs one, try this - it's simple but it works well and costs almost nothing: http://www.dealextreme.com/details.dx/sku.4439) It is almost certainly the limitations of such cheap testers that caused the confusion about this install in the first place. The correct pins are wired to the correct pins but with the same wiring error at each end. Thus the signals between the two sockets are not being sent over the twisted pairs of wires which is essential for the connection to work. I hope that the "installation engineer" that did this work has learnt something from his reliance on his cheap tester... -- Cheers Dave. |
#78
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Network wiring problem - weird one!
On Sat, 20 Sep 2008 12:16:18 +0100, Dave Liquorice wrote:
On Sat, 20 Sep 2008 09:43:29 GMT, PCPaul wrote: (Aside: if anybody needs one, try this - it's simple but it works well and costs almost nothing: http://www.dealextreme.com/details.dx/sku.4439) It is almost certainly the limitations of such cheap testers that caused the confusion about this install in the first place. The correct pins are wired to the correct pins but with the same wiring error at each end. Thus the signals between the two sockets are not being sent over the twisted pairs of wires which is essential for the connection to work. I hope that the "installation engineer" that did this work has learnt something from his reliance on his cheap tester... The perils of answering before reading the whole thread... Oh well, I do use a TDR for work testing and only use the cheapo for home jobs.. and I've never had the same colour swapping problem that this one turned out to be. Found plenty of bad connections and shorts with a cheapy tester, which TBH in a circuit that 'used to work' is all that's likely to happen. I have seen some cables with such small dabs of such faint colours that it was hard to figure out which was which without following it back to the twisted bits, though. |
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