I'm able to connect to Arduino+RAMPS through USB. I can even check end stops with M119. However, if I plug it to the power supply, my MacBook goes crazy and restart itself! Things I have tried:

• Uninstalled OSX, installed Ubuntu, I get readiness error when PSU is connected.
• Bought a new pair of RAMPS + Arduino.
• Run RAMPS all naked without anything on it.
• Measured PSU output, 12.2 V is stable.

I'm at a point I started to think my MacBook's USB ports are messed up. It is a 2008 model, do you think that would be right to blame?

Update

Tried a new and a very short USB cable: It worked for the first time, but laptop's trackpad gets very hard to control for some reason. Looks like I have to connect an external mouse.

I'm able to connect to Arduino+RAMPS through USB. I can even check end stops with M119. However, if I plug it to the power supply, my MacBook goes crazy and restart itself! Things I have tried:

• Uninstalled OSX, installed Ubuntu, I get readiness error when PSU is connected.
• Bought a new pair of RAMPS + Arduino.
• Run RAMPS all naked without anything on it.
• Measured PSU output, 12.2 V is stable.

I'm at a point I started to think my MacBook's USB ports are messed up. It is a 2008 model, do you think that would be right to blame?

Update

Tried a new and a very short USB cable: It worked for the first time and I'm able to home all axes, but laptop's trackpad gets very hard to control for some reason. I can only use an external mouse.

I'm able to connect to arduino+ramps through usb. I can even check endstops with M119. However, if I plug it to the power supply, my macbook goes crazy and restart itself! Things I have tried:

• Uninstalled OSX, installed Ubuntu, I get readiness error when PSU is connected.
• Bought a new pair of ramps + arduino.
• Run ramps all naked without anything on it.
• Measured PSU output, 12.2v is stable.

I'm at a point I started to think my macbook's usb ports are messed up. It is a 2008 model, do you think that would be right to blame?

Update

Tried a new and a very short usb cable: it worked for the first time, but laptop's trackpad gets very hard to control for some reason. Looks like I have to connect an external mouse.

I'm able to connect to Arduino+RAMPS through USB. I can even check end stops with M119. However, if I plug it to the power supply, my MacBook goes crazy and restart itself! Things I have tried:

• Uninstalled OSX, installed Ubuntu, I get readiness error when PSU is connected.
• Bought a new pair of RAMPS + Arduino.
• Run RAMPS all naked without anything on it.
• Measured PSU output, 12.2 V is stable.

I'm at a point I started to think my MacBook's USB ports are messed up. It is a 2008 model, do you think that would be right to blame?

Update

Tried a new and a very short USB cable: It worked for the first time, but laptop's trackpad gets very hard to control for some reason. Looks like I have to connect an external mouse.