My time capsule is flashing green and amber and I cannot reset it

I have a Time Capsule 2TB A1470, it was working fine but now is flashing amber and green constantly - I have tried all the reset procedures but it doesn't work. It flashes amber and green from the moment I power it up. No idea whether the thing is bust or just needs a different reset procedure. I've already tried the factory reset (holding button down with a pin and powering up). Help!