Windows 10 Cat 5 works on one desktop but not another


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I have a Del Dimension 4700 running on Win XP (service Pack 3 v.2002). It has a 4 (quad?)CPU running at 3.4 GHz with 2 GB RAM. (64 bit) Win is running off a 500 GB conventional Drive. It has two network adapters: 1394 Net Adapter (dial up?); Intel Pro/100 VE Network connection (Cat 5). It works well on the Internet.

My new-to-me desktop has an AMD Phenom (tm) motherboard with a II x 4 925 processor which clocks at 2.80GHz and has 8 GB RAM (64 bit). The win 10 software is loaded onto a 500 GB SSD. It has one network adapter built into the motherboard - Realtek PCle GBE Family Controller which, when attached to the same cat 5 connector as the fore mentioned desktop, does not recognize the cable. I used another cable in the same wall socket with the same results - no cable recognized.

I brought it to a a tech who reloaded Win 10 for me and updated the INet card software. He said the network adapter was working very well.

When I connected either Cat 5 cable (that also worked with the Pentium Desk Top) it failed to be recognized by the AMD desktop.

I suspect the end of the 1st Cat 5 cable is not compatible with the female socket of the AMD Desktop and the alternative Cat 5 cable doesn't work in the wall socket.

The Tech said the cat 5 arrangement should be the same for both computers and cables. My service provided says my High Speed Internet (Please don't laugh -- 25MHz) protocol is the same for all my computers and isn't the issue. He suggested I just purchase a medium quality WiFi Connector and be done with it.

Is there any way to determine where the quirk in my cable problems is? It's odd that it works for one but not the other even though both network cards have proved to worked reliably.
I guess I'm not sure why you'd be plugging an Ethernet cable into the wall. Are you talking about a phone cable? Phone cable will have 4 pins and Ethernet 8. These cables are not interchangeable. Ethernet cable standard hasn't changed so it definitely will work on any computer.
Is there any way to determine where the quirk in my cable problems is? It's odd that it works for one but not the other even though both network cards have proved to worked reliably.

Please take a clear picture of the connectors attached to that CAT5 cable (as in the image below) and of the wall socket and post them here on the forum so that we can take a look at them. Normally, the connectors attached to the cable should have the same wiring scheme in your case (the wires inside the connector should be in the same order).


You can test your network card with a RJ45 loopback connector and ping command:

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This is the best I can do for photos. My modem is in the basement and carries the signal via cat5 to the wall socket (right side) on the second floor of our home. I have a 30 foot cat 5 cable that plugs into the wall socket (images 8502 & 8500) and then into the computer elsewhere on the 2nd floor. image 8519 is an example of the end plug of the cat 5 cable. I purchased pre-made "Belkin" cables


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On the other hand where would I get a RJ45 loop back connector? How do I test for ping?
The wall sockets and the RJ45 connector look OK and since you have already mentioned that the other computer works well, it means the problem is rather on the AMD computer's side.

I've forgot to ask if the Network Adapter is enabled (on the AMD computer).
Please right-click on the start menu, then select Device Manager and do as in this video (from 0:25) to check:

Let me know if there are any yellow triangles with exclamation sign on them.

You can use Google to search for a RJ45 loopback plug or you can make yourself one. Buy a RJ45 toolless connector like this one:

and connect the wires as in this image (the blue and the green only, pins 1,2,3 and 6):

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