Could be the filament. It's been open for about 9 months (almost all used up now). But was stored in airtight containers with desiccant.

I took the entire dual extruder head out, thoroughly cleaned it. Cleaned the nozzles (heated them until anything in them was ash them cleaned them out). One PTFE tube was kinda clogged. Replaced it. Printed about 30 hours since and SFSG. But...I notice the LED lights in the cabinet blinking out occasionally and I have about 1200 hours on the unit.

I'm wondering if it could also be related to the power supply?
I ordered one off ebay. 24V - 14amps. It looks exactly like the one in my printer now.
http://www.ebay.com/itm/High-Quality...3D252618475097