Hi i have bought me a geeetech pro b. At first i wanted to change my z threaded rods and realized i cant change anything in arduino on the gt2560.
So i got me an mks sbase 1.3 but then i had extrusion problems. I could only print at 250C and even then the bowden extruder cant handle the force requiered.
Next i installed a new arduino ramps 1.4. With the same behaviour. (I choose on both boards the right Thermistor)
I also changed the power supply. 62amps
The heatsink fan is runing on 12 v


My Setup:
Geeetech Pro B
Arduino Ramps 1.4 Marlin
Bernis simple bowden extruder
E3D V6

post a link to your configuration.h so we can troubleshoot it for you.

heres the configuration.h

I think i solved tthe problem. Possibly it was just caused by a bad spool of filament. I tried the one that came with the printer and flexible filament and both worked.

But my controller doesnt get powered from the main 12v. Also if i connect 5v to the arduino it doenst even light up. But it works when i connect the usb cable to the arduino.
Any ideas

Either your ramps board doesn't have D1 installed or your mega board 5 volts regulator is fried. Both are common.

thanks i will investigate this