Geeetech

I have an earlier model A10 with the gt2560 revB board.

I have upgraded the extruder to a 3:1 geared Titan style (still bowden) - I am using the original geeetech extruder stepper in the gear drive.

I have reflashed firmware to reverse extruder direction (1.1.9 marlin) and change E-steps.

All is working except the extruder motor pauses for unknown reasons after the first couple layers then works only sometimes.

I have uncoupled the gear and removed filament to observe only motor, and it isnt mechanical problem - motor pauses often.

I have swapped one of the other axis drivers to E0 spot and the same problem.

If I plug EO cable into x-motor, x-motor does the same pausing/skipped steps.

I have plugged x-cable into extruder motor and motor works as expected.

I have tried changing E0 driver vref to .6v and raising it over 1.1v, and values in between.

Also, there is a red blinking light in front of E0 driver that comes on after a few seconds.

Are there any other ideas to try, or do I need a new board and possibly drivers?

Any help would be greatly appreciated.

One thing I thought of but am unsure about - is there a way that acceleration or kinematic settings in firmware could be causing E0 motor behavior?