Can't connect to C-7 hub

🎬 Get Started Using C-7
1

I bought a used C-7 hub. It was deregistered. When I plugged it in, it was only showing a blue LED and never turning green. I assigned a static DHCP IP for the C-7 MAC address. I was not able to connect to it. I used a small network reset button multiple times and made many restarts, and at some point it suddenly worked. I was able to connect to the diagnostic tool at port 8081 and made a soft reset. The LED started to turn green. This allowed me to connect to the hub, register and see a welcome screen. I successfully updated the firmware to the latest one. All was working fine but that was the last time I was able to connect to the hub. Then I decided to move the hub to its destination place, but wasn't able to connect. I moved it back, but with no luck.

I restarted the hub, router, and used the network reset button multiple times. I tried a different router. I tried a different power supply. My Hubitat reports the hub as offline and last seen when I was doing a firmware upgrade.

Is there anything else I can do?

2

Have you tried a different Ethernet patch cable?

1 Like
3

Have you tried a different Ethernet patch cable?

I used two of them in my test location and destiny location. Now I tried 2 more cables. No change.

When I power up hub I get blue LED, which changes to green. It's not responding on port 8081.

4

Did you set a static IP on the hub or set a reserved IP in your DHCP and leave the hub on DHCP?

You can try the network reset with the button under the hub again, it wont reset anything else, only the network settings.

What is the IP you set the hub for in DHCP and what is the IP of your PC you are trying to connect from? Did you try clearing the DHCP reservation in case that is the issue?

Try running arp -a from the command line and look for the MAC of your hub in the list.

5

I reserved an IP in my DHCP. I can't set a static IP on the hub because I can't connect to it.

I tried network reset countless times already. Blue and green flashes for a moment, then it turns to green, then blue and red, turns off and start "normally".

Router is 192.168.2.1. My laptop is 192.168.2.102.
Originally I asigned in DHCP 192.168.2.101 to the hub. Now it has 192.168.2.2 assigned.
On the second router I assigned 192.168.1.103 to the hub.
When it worked for a few minutes it was using 192.168.2.101

Edit: findmyhub finds the same IP even if hub is disconnected and reports some random IDs when wrong MAC is provided. So it's not a valid tool.

Did you try clearing the DHCP reservation in case that is the issue?

I cleared. I tried setting a different reserved IP. I used other router in 192.168.1.* subnet.

Try running arp -a

arp -a

Interface: 192.168.2.102 --- 0x4
  Internet Address      Physical Address      Type
  192.168.2.1           ec-3e-b3-c2-d7-a0     dynamic
  192.168.2.255         ff-ff-ff-ff-ff-ff     static
  224.0.0.22            01-00-5e-00-00-16     static
  224.0.0.251           01-00-5e-00-00-fb     static
  224.0.0.252           01-00-5e-00-00-fc     static
  239.255.255.250       01-00-5e-7f-ff-fa     static
  255.255.255.255       ff-ff-ff-ff-ff-ff     static
6

So your LAN has no devices on it? I get 20+ devices when I run that command.

Seems like maybe your laptop is having a problem communicating with other devices on the LAN.

1 Like
7

It's my test environment. There are only: router, laptop and C-7 hub in the network.

8

Ok, I thought the .2.x network was your main one.

When you connect the hub to the router, are you even getting a link light? Most routers/switches will have a LED that lights up when a device is connected to each port.

While highly unlikely, it seems like the ethernet port on your hub may be broken.

2 Likes
9

Thank you! I spent so many hours trying to understand what was going on. When I press the plug inserted into the hub firmly, push it upward and hold it in that position, everything works correctly.

Is there any instruction on how to take a Hubitat hub apart so I can replace the broken ethernet port?

1 Like
10

Ah, usually that is a problem for the micro-usb, have not heard of the ethernet port disconnecting from the board. It was an issue for early model C7 hubs which they reinforced once the issue was discovered.

I think the feet on the bottom may hide the screws to take it apart. From there you can reflow the solder on the ports and may wish to reinforce it with hot glue. I will see if I can find a post with more info.

Update: I found a post explaining how to take it apart which is as I said, screws under the 4 rubber pads on the bottom. I could not find any pics of the USB port repairs. Found the one about adding antennas which has some good pictures of the internals: External Antenna - #28 by lewis.heidrick

3 Likes