Alpine 9813 Keeps Shutting Off

I've had an alpine CDA-9813 deck for about a year and a half now and its been in my 97 civic the whole time.  Aftermarket speakers and an amp and sub are also in there.  The decks amp keeps shutting off on me.  The amp/sub stay on and keep playing, and the display shows no sign of a short.  Just my 4 speakers hooked up to the deck shut off.  When it happened first, I tried shutting off the stereo, and even turning off the car and removing the key, then turning it back on, but the problem persists.  Even when I leave it alone for a day it doesn't come back on.  It does work sometimes,  just very  randomly.  I thought initially that it was a speaker shorting out somewhere, so I faded the deck all the way to the rear, and balanced it to the left.  I shut the deck off, then turned it back on.  My logic being that as long as its not the rear left speaker causing the short that it should work.  But I still got no sound.  I tried balancing it to the right, and still the same thing.  Turning the deck on at low volume or mute doesnt help either.  I'm wondering if Alpine users have experienced problems with the decks doing this before.  I also tried shutting off the amp output on the deck, and I checked to make sure that the deck amp isn't set to be turned off as if I was using a 4-channel amp, and its not.  I checked all connections behind the deck, and there are no grounds there.  I'd like to bench test the deck as a last resort, since I recently soldered all connections behind my stereo.  The problem started before I soldered all of the connections behind the radio, so I didn't mess anything up there. 

Disconnect all four speakers in the car. Hook up a test speaker. Does the deck come on? If so you have a shorted lead and/or blown speaker. Hook the four speakers up one at a time until the deck shuts off. There's your culprit. If the test speaker does not come on the protection circuit in the deck has failed.