Possible odd motherboard ethernet port issue

Joined
Apr 27, 2020
Messages
5
Hello, I am a long time lurker but this is my first post. This will be a long post as I don’t know what my issue might be. For a summary of the issue, please scroll to the bottom of the post.

First off, I have been building my own computers for close to 20 years now as a hobby both for myself and for a few friends and family. Last week I upgraded my processor and motherboard from an i7 4770k to an AMD 3900X on a new Asus Crosshair VII Hero X470. I kept the same EVGA 750 W PSU and using a 1070 GTX card.

I built it, updated to the most recent bios and stress tested it with no issue. The computer is not overclocked and running factor settings except for the xmp profile for the ram. The ram timings have been tightened slightly. 4 days after the build, the wireless router that it is hard wired to fried. It was a western digital router and was about 3-4 years old. None of the lights on the router would light up, there was no WiFi network being broadcast and there was no internet connectivity on any of the hard wire connections. I replaced the router with a new Asus router. After a modem reset, all the networking worked perfectly with the new router. For four days. On the fourth day, the new Asus router is fried. When you turn the router on, the power light will come on, about 30 seconds later the light indicating an internet connection lights up briefly, than all the lights go out. During this time, there is no internet connectivity from any of the hard wired computers, there is no WiFi network broadcast and the computers on the wired connection are not connected to each other.

The router and computer are on the same circuit but separate surge protectors. The previous router worked well prior to the new computer needing only an occasional reboot. The power supply, graphics card, surge protector, network wiring, etc. are all unchanged. The computer is still fully functional and stable through all of this. My question is could this new motherboard be providing some negative feedback to the router causing them to fry? I have never heard of anything like this. If this is possible, is there a way I can check this?

Otherwise, is there something else that could be causing this and how could I check?

TL:DR: Upgraded to a new motherboard, fried two routers in 8 days. Is it possible for this motherboard to provide negative feedback to a router causing them to fry?
 

Markess

n00b
Joined
Apr 21, 2020
Messages
2
Hello, I am a long time lurker but this is my first post. This will be a long post as I don’t know what my issue might be. For a summary of the issue, please scroll to the bottom of the post.

First off, I have been building my own computers for close to 20 years now as a hobby both for myself and for a few friends and family. Last week I upgraded my processor and motherboard from an i7 4770k to an AMD 3900X on a new Asus Crosshair VII Hero X470. I kept the same EVGA 750 W PSU and using a 1070 GTX card.

I built it, updated to the most recent bios and stress tested it with no issue. The computer is not overclocked and running factor settings except for the xmp profile for the ram. The ram timings have been tightened slightly. 4 days after the build, the wireless router that it is hard wired to fried. It was a western digital router and was about 3-4 years old. None of the lights on the router would light up, there was no WiFi network being broadcast and there was no internet connectivity on any of the hard wire connections. I replaced the router with a new Asus router. After a modem reset, all the networking worked perfectly with the new router. For four days. On the fourth day, the new Asus router is fried. When you turn the router on, the power light will come on, about 30 seconds later the light indicating an internet connection lights up briefly, than all the lights go out. During this time, there is no internet connectivity from any of the hard wired computers, there is no WiFi network broadcast and the computers on the wired connection are not connected to each other.

The router and computer are on the same circuit but separate surge protectors. The previous router worked well prior to the new computer needing only an occasional reboot. The power supply, graphics card, surge protector, network wiring, etc. are all unchanged. The computer is still fully functional and stable through all of this. My question is could this new motherboard be providing some negative feedback to the router causing them to fry? I have never heard of anything like this. If this is possible, is there a way I can check this?

Otherwise, is there something else that could be causing this and how could I check?

TL:DR: Upgraded to a new motherboard, fried two routers in 8 days. Is it possible for this motherboard to provide negative feedback to a router causing them to fry?
Pardon me if you already checked this, but after the rebuild, did you plug the computer back into the exact same socket, and was the router on the same socket as well? Anything new plugged into any of the other outlets on the same circuit? Any chance that the circuit is wired backwards somewhere (hot wire on the outlet is where common should go and vice-versa) and it didn't cause an issue until now? If that's the case, maybe the power profile of the new motherboard was enough to create an issue that hadn't surfaced prior? Short of a circuit tester, its hard to tell that for sure. If you had any remodeling recently, that could be an indicator though.

Just thinking that the routers could have gotten fried on the AC side, as it would be really weird to have a power surge through a non-POE ethernet cable, but you said as much.
 
Joined
Apr 27, 2020
Messages
5
Yes, the computer was plugged back into the same outlet. The old router has stayed plugged into the same outlet the whole time. That circuit has this computer, my wife’s computer (i5 4670k w/1070 gtx), printer, computer speakers, modem, router and the garage door opener. Nothing new or different was plugged in before it after the computer build. Over the life of the router I have folded or mined with a 2080 ti and the 1070 (the 2080 ti has a waterblock and I was ensuring the new chip/ram/motherboard worked properly before putting the loop back in) with no stability or electrical issues. I was folding with only the new 3900X and one 1070, so less load than what this circuit has seen before.

I have not had any issues in the past. If there were a wiring issue, I’d have expected it to show up during one of the higher load scenarios than what it has been.
The only thing that is new/ different is the new computer build.
 
Joined
Apr 27, 2020
Messages
5
Additionally the last time any electrical work was done on the house was over two years ago when a few circuits were added.
 
Joined
Apr 27, 2020
Messages
5
Bought another new router. Have not connected the new computer to it. Seems like I’m going to be returning the new motherboard as I can’t figure out a way to test it and any shop I’d trust to take my computer to are currently closed due to the pandemic.
 

ryan_975

[H]F Junkie
Joined
Feb 6, 2006
Messages
14,788
Put a small cheap switch between the router and the computer. If the switch fries, something is definitely going on with the new motherboard (was it new or used?).

Also check the voltage at the outlets. And check for voltage/current on the ethernet cable.
 
Joined
Apr 27, 2020
Messages
5
I don’t really want to intentionally fry another piece of hardware and eat the cost. The motherboard is brand new.
Voltage at the outlet is 121.7 @60 hz with everything on at idle. While running prime95 and furmark, it was 120.7 @ 60 hz. This is according to my kill-a-watt.
I have split apart an Ethernet cable. I just gotta find my good probes to check the voltage. Otherwise I’ll have to make a little jig to hold them in place to make testing easier. Hopefully today.
 
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