ALIX to SG-4860 - b0rked

[ianr]

TLDR;

Migrating config from ALIX 2D3 to SG4860 failed. Unit is now non-responsive. HELP!

BACKSTORY:

I've been running pretty happily on an ALIX-2D3 for probably 4 or more years now. Seldom had any issues, save a laggy interface. Enter this summer when we finally have 0.5GB+ links available to residential (sadly, Canada seems to be lagging the civilized world for broadband), and my trusty home router ran out of steam. Wanting to future proof for gigabit, I opted to shoot the works, support the pfSense team and bought an SG-4860. Expensive, but I figured it should be no hassle.

backed up my config, hooked my MBP to the LAN of the SG, went through initial config, restore old settings…WHUPS. Error.
So I try powering it off, to restart. No DHCP lease this time (though my restored config should have that). Argh. hit reset to hopefully return to factory. Nope. No change. I have tried to connect to the console (in 2015, why isn't this microUSB?!). Boot process seems to hang after the "Welcome to pfSense" screen. Single user or Multi-User seems to make no difference. The last sign of life is show below.

"/boot/kernel/kernel text=0x1223df0 data=0x881ac0+0x3576a0 syms=[0x8+0x16f038+0x8
+0x16c47f]
Booting…
/ "

QUESTION;

While I'm not keen to reenter all of my settings, I would rather do that than sit here with a (very expensive) paperweight. Does anyone know how to take this to the out-of-the-box state so that I can start again? Or even how I can get the console to work so that I can do some hands-on repair of the failed import? I am reasonably *nix fluent once I have an interactive login.

Thanks in advance!

[cmb]

Guessing your ALIX config probably had 38400 for the baud rate (or something other than 115200), check your ALIX config backup in a text editor for the baud rate and change your console to match that. It's probably at an interface mismatch prompt on the serial console at a different baud.