Well, I'm guessing, but I'm thinking that this is a PLA2378 2000-watt M A X - P O W E R amplifier which is barely pushing 200 watts bridged, if that (2x15amp fuses, dead giveaway). So, pushing a couple of 12s, instead of sixes, might be a bit of a chore. That said, I was able to find the specs and what the indicator lights mean on this amp. I never assumed, needed to know. Green is good so back to the HU. I'm still not convinced that the amp didn't take a dump and is simply not in protect mode, that's possible. ANYTHING is possible in this scenario, guess we'll have to wait for the OP to get back to use.