Alpine Amp Problem

[ee904age]

Not quite car audio, but near enough. I have an Alpine MRV-1505 mounted in a boat running a 12" sub. It's always worked flawlessly until today. It hasn't been used since Easter and today after charging the batteries and powering everything up, the green power light flashes and I get nothing from the sub.

After a bit of googling it seems to be in protection? Where do I start looking for issues? All connections seem fine, since the boat is fibreglass both the positive feed and earth are run off the capstan winch feeds, that are 35mm2 welding cable from the battery in the back to the cabin in front. Battery reads 13.2v at the fish finder so I don't think that's the issue.

I've read that it could be RCA related, could it be that the terminals are corroded inside either head unit or amp? Neither are marine units but they are kept away from any water or salt spray.

[simonlenihan]

Try disconnecting the RCA's and speaker wiring and see if that makes a difference.

Have you checked the impedance of the sub at the box and at the amp?

Wouldn't hurt to check voltage at the amp with a meter too.