Increasingly, prints have been failing because of extruder/thermister decoupling. 

I haven't trouble shooted it much because I wasn't sure where to start.

Today, not a single print will finish.  About 30 seconds into the print, I get a decoupling error.

The hotend heats up ok, and the filament extrudes.  It is not until the hotend starts moving that I get the error.

I think I need to look at wires/solder joints.

The heating element is connected with Dean's connectors, soldered together.  The thermister is soldered to the stock wires that are connected to the daughter board.

I changed out the thermistor to an M3 screw in type.  I am now 23 hours into a print with no decoupling!