Does that mean that the control board is bad?
Should I try to re-flash it before I replace it?
There was a power failure and when the power came on it would not boot.
What kind of power failure was it? Was it just an outage or was it some voltage browning? Basically instead of 120V you were supplied like 60-90V and it fried most of your equipment due to the capacitors compensating for the loss of voltage with more current and frying themselves? If not ...
Then try and reset the unit first and see if you can login to the default IP. If that doesn't work then try and SSH into the unit. You can use software called PuTTY to do this.
Basically if you are able to flash it then it doesn't seem like its completely dead. Maybe just the settings were deleted.