Replaced Modem No Ethernet Connection

[Tenarrows]

I recently had a storm in my area which resulted in a power surge. It blew out my TV, Apple TV and Modem. I replaced the modem and it appears to be working. My router was not damaged. I'm able to re-acquire internet connection via WiFi on my Mac. So I conclude my new modem is working and my router is working. But I cannot get an ethernet connection by directly connecting my Mac to either the modem or the router. My Mac specs are OSX Yosemite 10.10.5

Open to suggestions. Thanks in advance.

 

[honestone]

Did you check the Network System Preference?

Also, after doing that, it might be good to shut down your Mac, the router, and then the modem. Wait the "specified" amount of time (your ISP typically has instructions as to how long you wait, and then the order the devices are turned back on).

 

[Tenarrows]

Thanks for the suggestions-

(1) I checked Network System Preferences and it says "Cable Unplugged (Which it's not) Either the cable for Ethernet is not plugged in or the device at the other end is not responding."

I deleted the Ethernet option in the left side panel and tried to "rebuild" a new one and still no connection.

(2) I unplugged the computer, modem and router. Disconnected all wires, waited 15 minutes, reconnected everything and started up my Mac and still no Ethernet connection.

 

[honestone]

Unless either your Ethernet port got "fried", or there is an issue with your Ethernet cable, that sure is strange. Here is what my Network System Preference Pane looks like on my late 2012 Mac Mini:

Although I am using High Sierra (OS 10.13.6), I suspect it looks the same for your OS. The connectivity "flow" is 1) Ethernet cable from the Ethernet port on the Mac MIni to the Ethernet Input port on my Netgear Router, and 2) Ethernet cable from one of the output Ethernet ports on the router to the Ethernet Input port on my Netgear modem. The connection for my ISP (Comcast) is from the cable outlet on the wall to the "cable input" port on the modem. (I also have a lmid 2017 13" MacBook Air, and as suspected, it connects to the internet, via WiFi, to my home network).

 

[Tenarrows]

Everything under "Using DHCP" is blank. I tried another ethernet cable and still nothing. Over the weekend I can move an old Mac into my office and try a direct connection with that machine, if there are no other options. That should at least determine if my affected Mac ethernet port was fried.

 

[honestone]

Yeah, that would be a good test. If it works with that older machine, then that could say there is an issue with the Ethernet port on the original Mac.

 

[Tenarrows]

Update: I brought my old Mac into my office and hooked it up directly to the modem and have an Ethernet connection. So it appears the Ethernet port on the other Mac got fried in the power surge, unless there's some other software issue unbeknownst to me.