Pre-Wired Ethernet Cable Works With One Router and Not With Another

Toggle sidebar Toggle sidebar
N

Nelno

Commendable
May 12, 2016
6
0
1,510
I just moved into a new house which has Cat6 wired from a central closet to every room. The cable I'm having issues with is about 10 ft from the closet, so there's no distance issue.

I have a TP-LINK TL-WR1043ND (version 1.x) router that's connected directly to my Arris cable modem.

This setup works fine, but I wanted to use it to provide a second access point so I bought a TP-Link Archer C7 AC1750.

I switched out the old TP-Link router for the Archer C7.

My XBoxOne (media room) connected to the Archer C7 via the pre-wired cable without any problems.

Both my laptop and PC, however, will not connect through a different pre-wired cable in a different room (study).

Both cables are connected directly to the router in the closet. Then a single cable connects from the wall jack in the room to the device.

I can plug the laptop into the RJ-45 jack in the media room and it works, using the exact same cable that doesn't work in the RJ-45 jack in the study.

I'm running Win 7 on both my desktop and laptop.

- I have power cycled everything, waited for modem to come up, then powered on the router, etc.
- I have tried all my tests with just the study connected.
- I have tried connecting the study to every port on the new router.
- I have tried 3 different cables in the RJ-45 jack in the study, none worked. One sees a connection but says "Unidentified network". The other 2 just constantly try to connect then fail saying "Cable unplugged". It seems to recognize there's a cable, then thinks there's no cable.
- the laptop and desktop have different NICs. One is a USB-based RealTek adapter, the other is motherboard Intel.

All of this points to a bad connection from the closet to the study, but the weird bit is that the closet-to-study cable works fine if I'm using the old TP-Link router. It just fails using the new router.

I can get about 95 Mbps to the study from speetest.net using the old router and I'm on a max 100Mbps connection, so it's pretty stable.

Any ideas why the older router would work but the newer would not?
Or any ideas on what I can do to debug this some more? I have a cheap network cable tester on order but it won't be here for 2 more days.
 
Solution
B
You likely will not find the problem with a cheap cable tester you need the really expensive ones that are used by professional cable installers.

What likely has happened is there is a connection that is just barely good enough that some devices can tolerate it but others can not. It could be that the wrong wire pairs are used but that is not a common.

You might get lucky and see that a connection does not appear tight but likely everything will look fine. Pretty much all you can do is pull the wire lose and re punch it down on both ends.
Sort by date Sort by votes
B

bill001g

Titan
Aug 9, 2012
28,318
2,754
125,640
You likely will not find the problem with a cheap cable tester you need the really expensive ones that are used by professional cable installers.

What likely has happened is there is a connection that is just barely good enough that some devices can tolerate it but others can not. It could be that the wrong wire pairs are used but that is not a common.

You might get lucky and see that a connection does not appear tight but likely everything will look fine. Pretty much all you can do is pull the wire lose and re punch it down on both ends.
 
Upvote 0 Downvote
Solution
N

Nelno

Commendable
May 12, 2016
6
0
1,510


Thanks, that's pretty much what I was thinking. I guess I was just hoping there was something simple I was missing. It's all under warranty so I'll call the company that wired it.
 
Upvote 0 Downvote
B

bill001g

Titan
Aug 9, 2012
28,318
2,754
125,640
That is strange most actual cable installers have a test meter and could give you a certification report that shows each port and how it meets all the required standards. If they did not actually test then your call to get it fixed should remind them that it takes much less time to certify every connection than to come back and fix just one.
 
Upvote 0 Downvote
N

Nelno

Commendable
May 12, 2016
6
0
1,510


It's new construction and the cabling has been in since pre-dry wall, so it's possible that this one was damaged somehow. It seems like almost every case of a contractor coming in to fix something end up messing up something else (had to re-plane the edges of the stairs -- took paint off the wrought iron railings, had to touch up paint on the cabinets - got paint spatter on the stainless steel stove, and the big one, final cleaning of the house - scratched 20 windows, 1 door window and a mirror in the master, all of which must be replaced.

I'm not looking forward to having anyone else come in to fix anything so I may try pulling the outlet and checking that and putting a new RJ-45 connector on the other end at this point -- depending on whether or not they say that will void my warranty.
 
Upvote 0 Downvote
N

Nelno

Commendable
May 12, 2016
6
0
1,510


But now that you mention it, I didn't get a certification report, but that may be because the company was mostly working with the builder / construction manager (i.e. I did not contract them directly). I will ask them if they made one.
 
Upvote 0 Downvote
B

bill001g

Titan
Aug 9, 2012
28,318
2,754
125,640


They may not have been a actual data cable installer they may have been a general electrician or one of his helpers. These guys treat wire as wire they don't know that data cable is much harder to install than tv coax or telephone wire.
 
Upvote 0 Downvote
N

Nelno

Commendable
May 12, 2016
6
0
1,510
My cable tester arrived today and it shows wire 6 (green, T568B configuration) is clearly bad.
I'm not sure why it's "good enough" for my older router, but maybe this cheap cable tester has a threshold low enough to detect it.
After inspecting both ends of the jacks they don't give me any reason to suspect they're broken, so it's time to get some wire pulled.
 
Upvote 0 Downvote
B

bill001g

Titan
Aug 9, 2012
28,318
2,754
125,640
They are not broken. The most common reason is that the wire is not making good enough contact with the jack. Maybe the insulation on the wire did not completely cut though when the jack was installed. You want to remove the wire cut off about a inch and reterminte it.

There is a chance there is a nail or something mid strand of the wire but that is not very common
 
Upvote 0 Downvote
N

Nelno

Commendable
May 12, 2016
6
0
1,510


I did visual inspections of the wire at both ends at it at least looked good, but I don't have any RJ-45 jacks (been 10+ years since I've used my tool for that). Hopefully that's all it is an no wire needs to be pulled. They'll be here tomorrow.
 
Upvote 0 Downvote
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom