Ethernet cable attached but no internet for a few minutes after PC bootup

[vaniac]

Hello!

I've had this anomaly where whenever I boot my PC up (no error messages or anything off/fishy pop up) and for a few minutes my computer does not recognize my plugged in ethernet cable. First of all, because it's a desktop PC, the ethernet cable is plugged in at all times, never removed. The computer is fairly new (as I had built it myself last year-ish).
The strangest part is that it doesn't happen every time, it happens at random intervals. As I do have multiple PCs in my household, I've confirmed that the ethernet cable is OK, as this problem does not occur on other PC's with the same ethernet cable. I've started to think that my motherboard is faulty.
What I saw today was something totally new. When I booted up, I quickly went to the Network and Sharing Center and my main Ethernet device kept blinking between the red circle with an X in it (no ethernet plugged in) and the Yellow exclamation mark (the blinking interval was somewhere between 5 seconds and lasted for ~2 minutes until it finally recognized the ethernet cable). I've laid my eyes on the I/O of the motherboard, focusing on the ethernet port and nothing seems off. Everything looks like it's supposed to look.
Could the problem have something to do with faulty drivers? I'm out of options at this point.

As for my computer specs:
Mobo: Asrock 970M Pro 3
CPU: AMD FX 8320
GPU: GTX 970
RAM: 2x4Gb
128gb SSD for boot files and a 300gb HDD
OS: Windows 10

The cable itself should be a standard issue CAT5, been using it for years without a single problem. The router I use is by Cisco (can't remember the model) but I'm more than certain that the problem is not in the router.

 

[Ralston18]

I would still try another ethernet cable just to get a different (perhaps tighter) fit into the motherboard's ethernet port. Make sure that both ends of the ethernet cable are snug and secure.

Have you run the built-in network troubleshooter to see what it finds and fixes? That may provide some additional information.

You might also check the Event viewer logs to see what, if any, warnings or errors occur just before or at the time connectivity is lost.

 

[vaniac]

I would still try another ethernet cable just to get a different (perhaps tighter) fit into the motherboard's ethernet port. Make sure that both ends of the ethernet cable are snug and secure.

Have you run the built-in network troubleshooter to see what it finds and fixes? That may provide some additional information.

You might also check the Event viewer logs to see what, if any, warnings or errors occur just before or at the time connectivity is lost.

I have ran the built-in network troubleshooter and doesn't give any results. It either says there are no problems or it's diagnosing the problem, but the connection will restore before it finishes diagnosing the problem. I've even let it diagnose for several minutes (even with internet) but not a single result.

Unfortunately trying a new cable is not possible, as the walls are solid concrete (? maybe, not 100% sure) and the cable runs through the solid wall. Router is in another room.

I'm going to look at the Event Viewer Logs the next time I boot up.

Thanks for the reply.

PS: The ethernet cable seems to sit snug in its port. There is very little (virtually close to none) room to move around. Looks pretty normal. Jiggling it doesn't seem to interfer with the connectivity. either.

 

[Ralston18]

Solid wall?

Just an ethernet plug terminated wire coming out straight to your computer or is there an ethernet wall outlet/port that your computer plugs into?

 

[vaniac]

Solid wall?

Just an ethernet plug terminated wire coming out straight to your computer or is there an ethernet wall outlet/port that your computer plugs into?

As I live in an old apartment, the cable literally comes out of the wall (had been drilled maybe?) from the other side. There are no outlets/ports on the walls in my apartment.
Basically the router is in the livingroom, the cable runs from there, through the wall via the drilled hole and in to my PC. A very poor engineering solution indeed, but that's what was done years ago.

 

[Ralston18]

Not at all uncommon.

So if the cable does work without problems on other computers then the cable can probably be excluded.

Are you using the motherboard's built in LAN adapter or a third party LAN adapter? If the latter, make sure that the adapter is fully seated and snugly in place.

Is there any way that you could borrow and install another LAN adapter to see if the problem continues. I.e., disable the motherboard's LAN adapter. If another LAN adapter works then the likely suspect would be the built-in LAN adapter and not the motherboard itself.

 

[vaniac]

Not at all uncommon.

So if the cable does work without problems on other computers then the cable can probably be excluded.

Are you using the motherboard's built in LAN adapter or a third party LAN adapter? If the latter, make sure that the adapter is fully seated and snugly in place.

Is there any way that you could borrow and install another LAN adapter to see if the problem continues. I.e., disable the motherboard's LAN adapter. If another LAN adapter works then the likely suspect would be the built-in LAN adapter and not the motherboard itself.

I have an update. I think I may have discovered the problem. It indeed is the ethernet cable.
As I booted my PC up, I didn't have internet for good 10-15 minutes and I fiddled around with the controls. Tried turning off automatic IP config (windows diagnose had told that there is not a valid IP configuration). That's why I started playing around with the IP config, but I made no progress. Now to the exciting part.
As I went to the back of my PC, I unplugged the ethernet cable and plugged it back in. I noticed something's off. My motherboard has two lights right in the ehternet port, I remember them turning on. But this time they didn't.
So there's no successful signal in to the port. I moved the ethernet cable around (focusing on the neck) and the lights went on and off (a good signal of a bad connection maybe?). At a certain angle the ethernet cable seems to work just fine.
It seems like the cable is the problem.
Now my plan is to get the ethernet cable crimpers and make a new head for the cable. I'm going to cut off a good 5-10 cm of length, just to be sure that I don't end up with worn out wires again. As either the wires in the cable have had too much stress at the neck part or the wires have worn out in the head part of the cable (don't know the English word for it as I'm not English). I've done these things before and won't have a problem with it. Makes sense right? The worn out part, because it's a 5+ year old cable.

 

[Ralston18]

Very good.

I think that the word you are seeking is "connector" - specifically an RJ45 connector.

Look at the existing connector and make note of which wiring standard (568A or 568B) is being used on the cable. Both ends must match.

Here are some images:

https://www.google.com/search?q=568a+vs+568b&sa=X&biw=1244&bih=687&tbs=qdr:y&tbm=isch&tbo=u&source=univ&ved=0ahUKEwi7ubi307nPAhUF0h4KHSQUAsEQsAQIGw

Just be sure to take your time and follow the guidelines for striping the wire ends, arranging them for insertion, and the final crimp.

Make take a couple tries so cut off as little wire as possible - maybe just 3 or 4 cm to start with....