Geeetech

I have a Geeetech I3 X. I had replaced the A4988 stepper drivers with DRV8825 and removed the 2 jumpers. They worked fine until I started heating up the heatbed and extruder. While heating, if I try to auto home the 3 axes, the motors make a HORRIBLE grinding noise and barely move (like they are being obstructed by something). I tried raising/lowering the voltage on the DRV8825s, which didn't help. I turned off the heatbed and extruder and the motors moved fine again. I put all the A4988 drivers back on and it worked normally again. My printer has a 15A power supply. Do I need to replace it with a 20A? What could cause this and how can I fix it?

take a look at the 12V rail on connector to your controller board. Assuming the GT2560 controller board is your controller board, the voltage may have dropped low enough for the voltage regulator (U2) to fall out of regulation. The 12V rail tot he processor can be easily read with a volt meter at the F1 fuse. With the heaters on and making the steppers go to home position the rail shouldn't fluctuate at all, if it does then your power supply will need to be beefed up.