Not sure what extruder that is, if you can get the heating block assembly off/out of the extruder it will be easier. Anyway, use a soldering iron on the heating block to get it hot, use a wooden pencil, piece of small dia. wood, plastic scraper to carefully remove melted filiment, the tip of the soldering iron will also melt and remove pieces. Wiping the hot mess with COTTON cloth can help remove the last of it, unless really burned on. A dual wattage iron works well and faster? too.
An ohm meter across the thermistor wires will tell you if fried/ broken wire, possibly why the flashing light, is what mine does, thermistor controls temp of heater cartridge and stops runaway. Needs to see thermistor complete circuit or will not put power to heater cartridge, some early printers didn't have this and sometimes did a runaway and burnt the house down. Ohm meter across heater cartridge wires will tell you if also fried/broken wires.
Anyway I am still figuring this here new fangled corntrappian out, G code, slicers, stl, stp,gst, gps, just show me where the oil goes, set the valves and we'll be good to go!
