Mini 2 Extrusion Issue

First generation Mini 2 extrudes about 10mm and then nothing.
Have completely disassembled and cleaned every part of print head (twice).
New nozzle.
Temp is sufficient.
Filament clamping tension as usual.
Stepper weakening?
Feeder gear slipping?

Suggestions Welcome!

Oops,
Heat sync fan got mounted backwards. Fixed now.