Extruder stepper freeze when hitting extrude in pronterface

Hi all my first post.

So i have two prusaI3 printers. One for plastic and one for experimenting with mig welding.

prusaI3 greg/wade Extruder Marlin ramps1.4

So while i was experimenting with mig welding i ran my extrude stepper really hard.
+#define DEFAULT_AXIS_STEPS_PER_UNIT {64, 64, 4680, 1100}
+#define DEFAULT_MAX_FEEDRATE {500, 500, 2, 178} // (mm/sec)
At one point i had the steps up to over 3000:
+#define DEFAULT_AXIS_STEPS_PER_UNIT {64, 64, 4680, 3000}

After playing around with that I set things back to normal and things ran fine for a while.
Then I set some different settings in slicer for different size filament
Next I tried printing with new filament and the extruder wasnt feeding.
So I pulled out the filament and tried to run the extruder empty.
I could turn the extruder gear by hand. I ran G1 E5 and the extruder turned normally, but when I hit extrude in pronterface it vibrates and barely moves.
I disconect reconnect the printer in pronterface, and I repeat the same scenaro with the same results.

Test:
I swap the ramps1.4 connections between x-axis and e0 extruder.
Result:
x-axis now behaves the same as extruder did freezing.
extruder now operates fine as the x-axis did

Test:
I swap the stepper driver between x-axis and extruder e0
Result:
The e0 extruder connection stepper still freezes
The x-axis connection stepper still operates fine
Test:
I measured resistance of capacitor and resistors under the stepper driver
Result:
They match resistors and capacitor readings under other steppers

Test:
I swap out ramps1.4 with my plastic printer
Result
The E0 extruder still freeezes same

Test:
I swaped out the Aurduino mega board with plastic printer
Result:
The E0 extruder still freezes same

Test:
I load working good marlin firmware from my working plastic printer.
Result:
The E0 extruder still freezes same

During all these test all other steppers perform normally.

I get frustrated and quit overnight.

I put my plastic printer back together.

Now my plastic printer extruder does the exact same thing both printers extruder freezes????????????

I'm lost
Please Help