I've been working on T174475 and flashed the firmware on scs-c1-eqiad on 2017-08-29, since the firmware update, I have not been able to connect to the scs console.
Please do not just powercycle this, as it could result in a dead scs. We need to check for serial console output, in case there was an issue with the firmware update and it requires user input.
They seem to take 5-6 minutes to flash firmware, but this has been offline and is still unresponsive to my attempts to ping/ssh/https connect to it. (Other scs consoles, like scs-a8-eqiad will respond to all 3.) Firmware has been updated on most of the remainder of our SCS console fleet without incident.
The CM4148 console server does have its own serial console redirection port on the front. Please attach a serial cable (using a usb to serial adapter to connect to your laptop) so we can troubleshoot if it needs input from that front. (You could also run it to a spare port on scs-a8-eqiad with a temp cat5 run, but using laptop seems easier. Can test laptop on scs-a8-eqiad, which is responsive so you'll know you have working usb-serial connection on laptop if needed.)
Basically troubleshoot with local means (serial redirection) and see if we cannot repair this scs console. This was purchased around 2014-05-07, so it is well out of any kind of warranty. If we cannot repair it, we will have to order a replacement.