Weird LAN Chip Malfunction

[AxisHax]

Is it possible that my motherboard's LAN chip isn't compatible with the new modem my ISP installed? Or is it more likely that the ethernet port is just broken?

For context, one of my computers' internet connection stopped working after the ISP installed a new modem in my house that's connected to optical fiber. When I plug the ethernet cable to the PC one of the LEDs blinks orange for a few seconds and then it turns off, but it works just fine with an old AIO I have in the same room.

The motherboard is an ASRock H110M-HDV R3.0.

Sorry for my bad English.

[mariushm]

Make sure your cable is properly wired.

Were you connected at 100mbps with the old equipment? If so, maybe it works fine with old hardware because only 4 wires out of the 8 in the cable are used for 100mbps, and maybe the new modem refuses to run at anything but 1 gbps, where all 8 wires must be in the right places in the connectors.

[manikyath]

sounds like a bad cable to me.

[AxisHax]

12 minutes ago, mariushm said:

Make sure your cable is properly wired.

Were you connected at 100mbps with the old equipment? If so, maybe it works fine with old hardware because only 4 wires out of the 8 in the cable are used for 100mbps, and maybe the new modem refuses to run at anything but 1 gbps, where all 8 wires must be in the right places in the connectors.

The old connection was kind of obsolete, I think we had 20Mbps and now we have a little more. The thing is that the same ethernet cable works with all devices I tried but one.

14 minutes ago, manikyath said:

sounds like a bad cable to me.

But it works with an older AIO, a laptop and a console.

[AxisHax]

25 minutes ago, mariushm said:

where all 8 wires must be in the right places in the connectors.

I bought the ethernet cable last year and it has been in the same computer since. The problem started the same day my ISP changed everything, the day before it was working just fine.

I called Movistar right after I noticed the problem, they told me to check if the cable worked with other devices and that if it did, then the problem was the computer and they had nothing to do with it. I'm wondering if the LAN chipset could be incompatible with the new connection or something like that.

[mariushm]

2 minutes ago, AxisHax said:

The old connection was kind of obsolete, I think we had 20Mbps and now we have a little more. The thing is that the same ethernet cable works with all devices I tried but one.

But it works with an older AIO, a laptop and a console.

But was it connecting at 1 gbps or at 100 mbps?

 

Both devices (at each end of the cable) must agree to connect to a specific speed. Maybe the old modem was only capable of 100 mbps, or maybe it was more relaxed and worked just fine at 100 mbps if the cable was faulty.

 

Your device (laptop, console, whatever) if it has a 1gbps port sends a message through the cable using the 1gbps connection scheme (all 8 wires) .

If the device at the other end (the modem from now on) only knows of 100 mbps (has only 4 wires out of the 8 connected to it) or the cable is faulty, the modem simply doesn't understand the message and ignores it.

A few moments later, your device (laptop, whatever) realizes it got not reply from modem so it falls back to "talking" through the cable the 100mbps way, using only 4 wires, and then your modem finally understands the message and replies and from that point, your laptop keeps talking to your modem at 100 mbps.

 

Your new modem may simply refuse to reply to messages if they're sent using the old 100 mbps way (only 4 wires), or your cable may be damaged or badly wired (bad connectors, wires in wrong order in the jacks etc) and the new modem simply doesn't understand the messages it gets from your computer so it ignores them.

 

 

 

[AxisHax]

9 minutes ago, mariushm said:

But was it connecting at 1 gbps or at 100 mbps?

 

Both devices (at each end of the cable) must agree to connect to a specific speed. Maybe the old modem was only capable of 100 mbps, or maybe it was more relaxed and worked just fine at 100 mbps if the cable was faulty.

 

Your device (laptop, console, whatever) if it has a 1gbps port sends a message through the cable using the 1gbps connection scheme (all 8 wires) .

If the device at the other end (the modem from now on) only knows of 100 mbps (has only 4 wires out of the 8 connected to it) or the cable is faulty, the modem simply doesn't understand the message and ignores it.

A few moments later, your device (laptop, whatever) realizes it got not reply from modem so it falls back to "talking" through the cable the 100mbps way, using only 4 wires, and then your modem finally understands the message and replies and from that point, your laptop keeps talking to your modem at 100 mbps.

 

Your new modem may simply refuse to reply to messages if they're sent using the old 100 mbps way (only 4 wires), or your cable may be damaged or badly wired (bad connectors, wires in wrong order in the jacks etc) and the new modem simply doesn't understand the messages it gets from your computer so it ignores them.

 

 

 

With the old modem my PC's ethernet port had an always-on green LED and an orange one, which according to the motherboard's manual it means it was running at 100Mbps. The LAN chipset is capable of 1Gbps, so the modem was the limiting factor.

[AxisHax]

23 minutes ago, mariushm said:

Your new modem may simply refuse to reply to messages if they're sent using the old 100 mbps way (only 4 wires), or your cable may be damaged or badly wired (bad connectors, wires in wrong order in the jacks etc) and the new modem simply doesn't understand the messages it gets from your computer so it ignores them.

What should I do then? I was thinking about getting a dedicated network card.

[beersykins]

Most of these responses have no idea what they're doing.

 

Did you ever force speed/duplex?  Make sure your nic is on auto.  If your nic only ever negotiated at 100 mbit before with gigabit on both sides then test with a different cable.

[AxisHax]

1 hour ago, beersykins said:

Most of these responses have no idea what they're doing.

 

Did you ever force speed/duplex?  Make sure your nic is on auto.  If your nic only ever negotiated at 100 mbit before with gigabit on both sides then test with a different cable.

I've never changed any network-related setting. Currently I have a Cat 5e cable, should I get one of a higher category?

[AxisHax]

18 hours ago, beersykins said:

If your nic only ever negotiated at 100 mbit before with gigabit on both sides then test with a different cable.

What cable should I get? Is Cat 5e alright?

The computer isn't close to the modem, so I need to get 10 meters of cable at least and test it before rewiring through the walls.