It would appear that it is dead. Sat in the shop unused for a long, long time.
Connected it and got a very low volume initially, and now it has nothing.
Thinking I'll open it up and either get a plate amp that might fit it, or will turn it into a passive sub.
IF I can get the old plate amp out of it. I've removed every screw possible and it's not coming out so far. Next step is my trusty hammer and chisel...LOL