In my case the servo move a little bit the machine connect to the pc after no.
I use this servo : Turnigy 620DMGplusHS High Torque Digital Servo
I have forgot but I have change the logic fuse of 5A for on of 10A, I had problem when I have upgrade with dual extruder. Perhaps it will help you.
If you have a 5volt on your power supply (with commun ground between the rambo board (servo gound pin) and power supply 5volt ground) try to plug your servo on this output.
I'm not an expert ... I explain you only what I have do and try to understand the difference between our machine setting ...
I use this servo : Turnigy 620DMGplusHS High Torque Digital Servo
I have forgot but I have change the logic fuse of 5A for on of 10A, I had problem when I have upgrade with dual extruder. Perhaps it will help you.
If you have a 5volt on your power supply (with commun ground between the rambo board (servo gound pin) and power supply 5volt ground) try to plug your servo on this output.
I'm not an expert ... I explain you only what I have do and try to understand the difference between our machine setting ...