Help! - crazy ethernet cable problem!

[Sirius]

Hi - my internet was working fine - then last night I couldnt connect because Windows 7 said my ethernet cable wasn't connected.
I have a D-Link ADSL2 modem - and the LAN light doesnt come on.

Troubleshooting already tried:

• Using same cable connected my Mac to the Modem - internet worked fine (but my Mac is so old I can't use a lot of websites)
• Using same cable connected my Windows XP machine.. LAN light on.. but no internet connection (cable unplugged message)
• Trying a different ethernet cable
• Unistalled/reinstalled network card on Windows 7 machine and restarting
• Unplugged everyting, turned off modem at power, restarted.. shut down.. 2 times

So the cable seems ok, the modem seems ok, the network card seems ok, and it worked 2 days ago but now.. nothing.
Is there a way to check whether the ethernet port is working?
Any suggestions as to how I can fix this pesky problem? Or at least diagnose what the problem is? Could it be interference from software? Very perplexing
THanks in anticipation...

 

[Jonathan_King]

Welcome!

It sounds like a bad network card. Try buying a cheap one on Newegg: Newegg.com - Rosewill RC-400-LX 10/ 100/ 1000Mbps PCI V2.2, 32/64-bit, 33/66MHz Network Adapter 1 x RJ45 - Network Interface Cards

 

[aem]

You could test the ethernet port by doing a cross-over cable from the problem machine to another. Just connect the ethernet cable (cat 5) from one machine port to the other.

Configure the tcp/ipv4 of problem machine:

Ip - 192.168.1.20
Subnet - 255.255.255.0
Default Gateway - 192.168.1.1

Configure the tcp/ipv4 of working machine:

Ip - 192.168.1.21
Subnet - 255.255.255.0
Default Gateway - 192.168.1.1

Make sure the port lights are on (ie showing green)

Then from one machine test ping the other using the above IPs.

 

[zap]

Shell to a command prompt with elevated privileges if needed, and type the following:

ping localhost
ping www.google.com

ipconfig /all
ipconfig /all | more
cls

ipconfig /release
ipconfig /renew

Let us know how it goes.

I also like the previous posters idea using a crossover cable . . . clever. If you currently have Cat5/6 cables that are not crossover, you can purchase a crossover adapter relatively inexpensively.

 

[RedBirdDad]

I agree with J_K, sounds like a bad ethernet card. Fortunately they're pretty cheap.

 

[Sirius]

HI - Thanks for the suggestions everyone.. I have tried a few of them
Took my computer back to the seller - checked out the network card and it connected to his net there with no problem.. so not the card??
Rang the ISP - I am connected at their end no problem.. did some tests on the modem and it seems that may be where the problem lies. However, my mac connects to the modem and net with no problems so that seems a bit weird.

It is all very frustrating because I can't seem to analyse what is wrong with my LAN. (all windows 7 says is that I have a faulty ethernet cable... no other diagnosis)

If anyone has any further suggestions then I would be grateful.

 

[Jonathan_King]

Have you tried aem's suggestion? http://www.sevenforums.com/network-sharing/63079-help-crazy-ethernet-cable-problem.html#post563988

That will eliminate the router from the list of possibilities.

 

[Sirius]

No I havent tried that one - not sure what a cat5 ethernet cable is??
I will try it tonight though... I just wish I knew how to fix this pesky problem

 

[Jonathan_King]

Just run a network cable from 1 PC to the other.

 

[RedBirdDad]

HI - Thanks for the suggestions everyone.. I have tried a few of them
Took my computer back to the seller - checked out the network card and it connected to his net there with no problem.. so not the card??
Rang the ISP - I am connected at their end no problem.. did some tests on the modem and it seems that may be where the problem lies. However, my mac connects to the modem and net with no problems so that seems a bit weird.

It is all very frustrating because I can't seem to analyse what is wrong with my LAN. (all windows 7 says is that I have a faulty ethernet cable... no other diagnosis)

If anyone has any further suggestions then I would be grateful.

One item we haven't thought about is if the ethernet port on the modem is starting to go. It's rare but it can happen. If it's starting to have problems auto detecting the ethernet connection it may look like a bad card.

It might be worth locking the speed/duplex on his network card and hooking it up again.

 

[Sirius]

Hi everyone - I have tried all the suggestions now.. I pinged successfully from one machine to the other and back again using AEM's suggestion. So not the cable - not the card - not the port on the PC???

So I thought.. must be the modem!

Went and bought a new one.. same problem... Have connection to outside world but my computer just won't communicate with the modem and the only solve that Windows 7 offers is to plug my ethernet cable in. I have done all the tests so I am wondering what on earth the problem is???

Does anyone think it may be a virus or something? mmm it is most frustrating!

 

[aem]

You said "Have connection to outside world", this means it is going out through the modem.

So you have all the machines hooked up to this modem, and they all have internet accesses. Just cannot connect from one Pc to another, using map drive?

 

[Sirius]

You said "Have connection to outside world", this means it is going out through the modem.

So you have all the machines hooked up to this modem, and they all have internet accesses. Just cannot connect from one Pc to another, using map drive?

No I can connect one pc to another - no prob there.

By 'Connection to the outstide world' what I meant was that my modem is connected to my ISP (ie the status and ADSL lights are working and my isp shows me as active)
I cannot connect to the internet from my PC.

The LAN light doesnt light up on my modem and all Windows tells me is I need to plug in an ethernet cable (see previous posts on all the tests I have done on that).

I can't work out why the LAN isnt working.

 

[Staple Head]

unless i missed it i assume you have a router? if the is the case unplug the router from the modem and plug the problem machine directly into the modem. your isp should have asked you to do this.

 

[aem]

Well this narrows it down a fair bit. You already know the ports on your machine work, cos you can cross-cable with it. The cable also work. So then the modem port could be dead. I assume you tried other ports on the mode (is it multiport)?

Can you do ipconfig /all and privde the details?

 

[Sirius]

I thought it might be the modem - so I bought I new one... didnt make any difference
I will do the ip config thing and post it... I am not in front of the troublesome pc at the moment

 

[RedBirdDad]

This is getting more and more bizarre. At this point it sounds like the only device that can't connect to the modem is the W7 machine yet it can connect via cross cable to another computer. Jeez!

You know, it's going to turn out to be something simple and we're all going to smack foreheads and let out a *DUH* when it get fixed... certainly...eventually...hopefully...maybe... ?????

What you're missing here is a router. It's really a much safer and better way to connect computers to the internet anyway. They're also dirt cheap nowadays.

If you can lay your hands on one, it's worth the cost. You may never know what the problem is but if the router gets around it, well that's what's important anyway. Getting internet access back.

 

[aem]

Ok so the direct cross-over cabling work, what about connecting the computers to the ports of the modem and try connecting between the machines? Basically using the modem as a hub.

 

[RedBirdDad]

I see two different DLink ADSL2 modems. One with a single ethernet port (DSL-2320B) and one with 4 ports (DSL-2540B). Something tells me he has the single port model.

 

[Sirius]

Hi - I have the 4 port ADSL2 504T Generation II DLINk Modem Router.
How do I connect the two machines and see if one will talk to the other? Will this work if the W7 PC doesnt even think it has an connection to the modem at all?
Someone suggested it could be the network plug (port?) Does anyone know how I can test that.
THis problem is most frustrating as everything seems to work (the network card, the cable, the modem) but they just won't all talk to each other.
(My old MAC is connecting fine.. LAN light on and everything - its VERY weird)