Mk3s stops extruding, then starts printing again, and some time extruder motor is stuck?  

Mk3s stops extruding, then starts printing again, and some time extruder motor is stuck?

I had a mk3 and had the same problem. (see below)
Rebuild the hot end, it did not solve the problem.
After braking wires(mk3), I rebuild almost the whole printer to a mk3s.
All new bearings, new hot end(everything), a lot of new plastic parts(z motor lower and higher parts,
whole extruder parts, and more).
Cleaned rods, put grease on bearings(new), 2 old bearing were bad.
Replaced extruder gears, but now I think the old ones are good.
All cables to extruder are new, except pinda probe(forgot to order), all fans are new.
Heatbrake is a standard e3d.
On extruder motor I have a fan mounted to cool the motor.(37 C degrees wen printing PLA). Doors are open.
Temperature with ABS is 57 C degrees after 2 our printing in a enclosure.

The new printer wizard worked in one go, all is perfect.
Printing looks very good and feels very good.
Firmware is the latest model and it is the mk3s firmware.

This happens, on the old printer it was the same!!!!!!

After long searching I find out that the power setting for extruder motor is different in quality
and speed settings of prusa slicer.
I did a search on how to set this in the slicer, to do a few tests.

Benchy printing as test model.

PLA quality print standard settings -
-2x prints fails, extruding stops, but printer moves on and starts printing again, some lines are missing.
-1x print fails, extruding stops,and never starts again, unload filament, I hear the motor turning,
but on front extruder the axis(round steel axis) does not move, filament is stuck, after pulling
real hard the unload works, filament looks like the beginning of a roll, nothing is melted or thicker,
looks like the extruder motor is stuck.

PLA speed setting standard setting-
- 1x print the whole model, 1 line missing.
- 1x prints whole model perfect without faults.

PLA quality setting standard, change start gcode M907 E580(standard is E430)(speed is E538)
-1x I hear clicking sound, very soft clicking sound, but I am not 100% if the E538 is working were I put it in the startup code,
printer prints model, print is missing lines in the print.
-1x Trying to put the higher power in a different place in the slicer code, looks like this is working, model is a good print.
-1x Same as above , one line is missing, extruding stops , printer is still moving, I stop the printer,
and unload does not work(3 times), then I did pull real hard and then unload works again, see picture of filament tip that was stuck.
-1x E600, benchy print is good.
-1x E600, benchy print is good.

Now printing several beds full of models , seems to work with E600.
Possible the E600 is working I need to do some more tests to see if it is stable.

Where did I put the E600, in prusa slicer software, section "printer settings" - "Start gcode" section,
At the end there are E.... numbers , this I change to E600,
If you have a self made setting without quality and speed in the name use "M907 E600".

Question:
How to solve this?
Is there a better place to put the power settings?
What is the highest I could go, with the power setting, what is safe.

How to test if extruder motor is bad?

I think this could be the problem, the extruder motor, or power supply, or einsy board, but how to test this?
Wen extruder motor is clicking the power 24 volts is stable on the printer screen.