Both Ethernet ports suddenly stop working on ASUS Sabertooth Z97 Mark 1

[giygaskeptpraying]

I was having problems with my modem and router after they both lost power for a split second during a thunderstorm. Couldn't get the modem to communicate with the router no matter what (the modem has an ethernet activity LED indicator that didn't flash when the router was connected, meaning it wasn't sending any data). So I had to connect my computer's ethernet directly to the modem to get internet access (here the ethernet LED was flashing as expected) and left it like this for the rest of the day.

I put my computer in standby and noticed that the ethernet light stopped flashing again. I thought it might be because the computer was in sleep, but when I woke it, the light still wouldn't flash and that's when the ethernet ports died. The orange light in the port doesn't even light up.

My mobo has two, an Intel and a Realtek port. Ever since I got it I've been using the Intel port. The Realtek one now doesn't show any signs of activity at all when I plug in the cable. When I plug it in the Intel one, the orange light flashes for half a second before going dark, then flashing briefly again, indefinitely. I can see the taskbar network icon go from a red X briefly to the yellow ! triangle, then back to red, etc.

This is supposed to be a super reliable and durable motherboard but it hasn't even lasted one year without problems

 

[beegmouse]

The light will go out if either device fails, the router or pc, so it could be either.

Lightning strikes do happen, and do cook electronics. I suspect the router most, as it is the point of entry to the building for the phone line. try connecting a short ethernet cable from the pc to a laptop, see what happens.

 

[giygaskeptpraying]

The light will go out if either device fails, the router or pc, so it could be either.

Lightning strikes do happen, and do cook electronics. I suspect the router most, as it is the point of entry to the building for the phone line. try connecting a short ethernet cable from the pc to a laptop, see what happens.

Sorry I may not have made it clear, but my problem is happening with the computer connected via ethernet straight to the modem. The router's out of the picture now, pretty sure I'll need a new one.

 

[termathor]

The light will go out if either device fails, the router or pc, so it could be either.

Lightning strikes do happen, and do cook electronics. I suspect the router most, as it is the point of entry to the building for the phone line. try connecting a short ethernet cable from the pc to a laptop, see what happens.

Sorry I may not have made it clear, but my problem is happening with the computer connected via ethernet straight to the modem. The router's out of the picture now, pretty sure I'll need a new one.

You need to elementary test every com port of your PC and your router and modem that was on at time of thunderstorm against a "clean" port/DSL line.
It may be your network equipment ports are toast or your PC's or both.

Was the PC ports plugged in your active equipment when there's been power blink ? if yes, which port was it ?

 

[giygaskeptpraying]

You need to elementary test every com port of your PC and your router and modem that was on at time of thunderstorm against a "clean" port/DSL line.
It may be your network equipment ports are toast or your PC's or both.

Was the PC ports plugged in your active equipment when there's been power blink ? if yes, which port was it ?

What do you mean by testing it against a clean port?

I don't think the storm damaged my modem or PC because those two were still working for hours afterward. Yes, everything was plugged in when the power blink happened. My monitor flickered and my PC never even lost power. It was only after I put the PC in standby later at night, and woke it back up when the ethernet stopped working.

 

[termathor]

You need to elementary test every com port of your PC and your router and modem that was on at time of thunderstorm against a "clean" port/DSL line.
It may be your network equipment ports are toast or your PC's or both.

Was the PC ports plugged in your active equipment when there's been power blink ? if yes, which port was it ?

What do you mean by testing it against a clean port?

I don't think the storm damaged my modem or PC because those two were still working for hours afterward. Yes, everything was plugged in when the power blink happened. My monitor flickered and my PC never even lost power. It was only after I put the PC in standby later at night, and woke it back up when the ethernet stopped working.

I mean:
- test your then connected PC port against an element that couldn't be impacted (another switch)
- test your then connected modem port against an element that couldn't be impacted

Reason is any of the then plugged port could have been damaged, therefore it is neccessary to proceed step by step.

By the way, it's not only a power blink issue, you also have power surge via DSL lines or even ethernet cabling.
I've seen DSL modem have their DSL port toast, also switch ports get toaste via inducted power caused by lightning.

 

[giygaskeptpraying]

I mean:
- test your then connected PC port against an element that couldn't be impacted (another switch)
- test your then connected modem port against an element that couldn't be impacted

Reason is any of the then plugged port could have been damaged, therefore it is neccessary to proceed step by step.

By the way, it's not only a power blink issue, you also have power surge via DSL lines or even ethernet cabling.
I've seen DSL modem have their DSL port toast, also switch ports get toaste via inducted power caused by lightning.

Okay thanks, I will try that.

But why do you think the ethernet connection to the modem was still working after the power surge, and suddenly failed hours later?

 

[termathor]

I mean:
- test your then connected PC port against an element that couldn't be impacted (another switch)
- test your then connected modem port against an element that couldn't be impacted

Reason is any of the then plugged port could have been damaged, therefore it is neccessary to proceed step by step.

By the way, it's not only a power blink issue, you also have power surge via DSL lines or even ethernet cabling.
I've seen DSL modem have their DSL port toast, also switch ports get toaste via inducted power caused by lightning.

Okay thanks, I will try that.

But why do you think the ethernet connection to the modem was still working after the power surge, and suddenly failed hours later?

No idea, really. Admitedly, it's a wee bit fishy. But end of the day, you lost connection, right ?
Maybe the circuit died a bit later ...

 

[helpstar]

did you restart your PC? not just shutdown and boot up, please try a restart of windows.

reset the BIOS (clear cmos)

enable the realtek ethernet port inside BIOS and install realtek lan drivers

reinstall intel lan drivers

did you test another lan cable?

do other PCs/Laptops run with the modem via lan?

 

[giygaskeptpraying]

did you restart your PC? not just shutdown and boot up, please try a restart of windows.

reset the BIOS (clear cmos)

enable the realtek ethernet port inside BIOS and install realtek lan drivers

reinstall intel lan drivers

did you test another lan cable?

do other PCs/Laptops run with the modem via lan?

Looks like the problem was with the modem's ethernet port. I connect several different devices to it and it wouldn't work with any of them. Had to get a new modem.

 

[helpstar]

Did you reset the modem? Did you unplug power, waited about 1 minute and then tried it again?
Firmware of the modem reflashed?

 

[giygaskeptpraying]

Did you reset the modem? Did you unplug power, waited about 1 minute and then tried it again?
Firmware of the modem reflashed?

Yep, over a dozen times.

I thought the problem was with the motherboard's ethernet ports because those were working until they suddenly became unresponsive. After testing them separately, with several different ethernet cables, it became clear that they weren't the problem.

I connected a router, a desktop, and a laptop to the modem's ethernet port and it didn't respond to any of them.

 

[helpstar]

so you did reset the modem to factory default and flashed the firmware too?

 

[termathor]

Did you reset the modem? Did you unplug power, waited about 1 minute and then tried it again?
Firmware of the modem reflashed?

Yep, over a dozen times.

I thought the problem was with the motherboard's ethernet ports because those were working until they suddenly became unresponsive. After testing them separately, with several different ethernet cables, it became clear that they weren't the problem.

I connected a router, a desktop, and a laptop to the modem's ethernet port and it didn't respond to any of them.

Seems you found the problem, then. In case of lightnings, the closer an equipment is to the phone/DSL/cable line, the more likely it is to get power surges, because they can come from either power, or data lines.
This is coherent with your findings ...

Happy you found the cause 🙂