Hi… I might start testing by first disconnecting the Arduino from the ramps board and plugging it into the computer all by itself. If the laptop shuts down, the arduino needs some work. If not, then connect the ramps… if it shuts down at that point, the ramps needs help. If it’s ok at this point, turn on the power supply and see what happens.
If the arduino shut down the laptop you likely have a blown regulator and it’s drawing too much power over usb. You should find that two little chips next to the usb port get very warm very quickly.
If the ramps shuts it down, then something is shorted in the ramps board and we’ll need to start looking for how that can happen… probably the diode under one of the stepper drivers. Possible the diode that you can see near the edge.
Attach a picture of the front and back of the arduino and the front and back of the ramps.