PC keeps losing internet access.

[atlasmike]

I had a customer call me about her PC not being able to access the internet. The PC is a Lenovo H520 desktop running 8.1. She said that her ISP (who she called first to see what the problem was) told her that the Ethernet has no valid IP configuration and that the Ethernet card need to be replaced (no Ethernet card, it's built in) or she should buy a new tower. So I go to her house to see if I can fix it there. I do a few things to see what worked, like resetting the router etc and nothing. So, not wanting to spend too much time there, I take it to my shop. I hook it up to my network and it still shows limited connectivity for the network. I run a virus scan to see if there is some malware blocking the connection. That didn't come up with anything. The next thing I did was ipconfig /release and then ipconfig /renew and when it finished the renew process it said that it could not connect to the dhcp server.

Next I run: netsh winsock reset catalog
netsh int ipv4 reset reset.log
netsh int ipv6 reset reset.log

And then rebooted the system. It connected to my network and I was able to access the internet unabated for two days and I rebooted the system many time to see just in case. It seemed to work just fine after that.

I take it back to her set it up all nice like and start it up and back to limited access again. So I reset the winsock, ipv4 and ipv6 again and BAM, back on the net. For now. lol. She calls me back today to say it was back to limited access. I think it may be the modem that she is connected to. Maybe changing the DHCP server setting? Should I set it to a static IP address? I told her to call her ISP to bring a new router/phone/modem out to her. What else could I try if the new modem doesn't work?

 

[tek9]

Try a USB Ethernet adapter and see if that helps. Might actually be a bad NIC.

 

[glennd]

i got a laptop today with a dead ethernet port (NIC). you don't see that very often but it does happen.

 

[frederick]

Could be the NIC as mentioned, could be the router. Try the USB to Ethernet adapter, if it repeats, then it could be the router. I've got a client that's gone through 3 routers in 3 years because they have it between the refridgerator and a microwave. Told the client things have to change, cause I'm tired of telling her what's wrong and yet I'm still to blame.

 

[datadatau]

One other thing that is really unusual, but I have seen before.

Check to see if the router is a 10/100 bit router. I have run into this once before, where the pic nic was a gigabit nic and was causing the random issues you described. Issue was resolved by forcing the nic in the properties to only operate at 100.

Back in the old days when 10/100 first came out, there were a lot of nic cards that were only 10, and we would have to force the ports to only work at 10 because the switch would actually loose the packets since it was talking too fast for the nic, When I ran into the issue you described above, I had a client that had actually used 3 other technicians trying to resolve the issue, I checked it out, brought it to my shop and did what you described and it seemed to fix the issue, took back to the client and again the issue appeared, did the resent and boom everything seemed fine, the next day, same issue. Finally remembered about the old days and looked at the router and realized that it was a 10/100 only router. Set their nic on the pc to only work at 100, and it has been over a year, no further issues.

Good luck.

 

[cypress]

I've had that issue happen to me twice. The resolution: turned out to be a bad NIC. Sometimes they just short out.

 

[atlasmike]

Well What I will do is grab a NIC from one of my spares around the shop and install it for her to see if it works and by pass the NIC built in to the Mobo.

 

[joemessman]

Go to power management on the NIC settings and disable it from going to sleep.

 

[Bootman 650]

@atlasmike - Should I set it to a static IP address? I told her to call her ISP to bring a new router/phone/modem out to her. What else could I try if the new modem doesn't work?

Think that's your best option. Regardless of the the actual cause, you will find setting a static IP address can cure all sorts of network problems. Does she have any other devices on the network that it may be conflicting with?

 

[nlinecomputers]

It didn't work for a awhile on your bench. Can't see a router being the issue if it fails,even briefly, in shop and on site. Sounds like a bad NIC to me. Test with a Linux disk to confirm. Also check error logs for information.

 

[frederick]

I avoid static IP's if I can

 

[atlasmike]

I talked to a my buddy who is an account manager with a local IT firm around my area. He said he had the same problem with his wife's computer as well (a lenovo as well I think). He said uninstalled the factory installed Norton. That was blocking the NIC for some reason. And he turned off ipv6 as well. So I did the same and no problems since. I just used the Windows Defender that comes with the PC. I called her back a few days later and still worked fine. And I still haven't heard from her for that particular PC. I have another that I am working for her right now. So thanks guys. Maybe this can help you out if you come across this in the future.

 

[JustInspired]

Norton huh? Who would have thought.