just to be clear, on flash recovery...
you held down S1 whilst powering on the board, and kept it pressed down... do you see LEDS blinking? or what happens?
then once powered up, start axoloti, go to select device... do you see NO devices listed? or some device with DFU in the name.
(make sure you have nothing else connected to board, and the axoloti is connected directly to your computer)
also be good to get some other general info...
- any lights coming on?
- have you connected anything to the gpio pins?
- version of axoloti software/ operating system?
- what version is your board? when was it shipped?
as far as i know, the only (rare) board failure that has been seen is for the the v1.0 boards, and is described here
(it sounds like this is not sure issue - since in the above issue, users are able to still see the board, but you say you cannot... but I thought id raise it, as its the only failure I know of)
is your board a v1.0 , it printed on the board, and would have been from the initial crowdfunding batch or shipped before December 2015.