No connection to Fortigate 200D through console

Hi everyone,

I'm new to Fortinet devices and got a Fortigate 200D for free from a friend to play around with. I'm trying to establish a connection to it through the console port. I have an RJ45 plugged into it and my laptop, using putty as the console software. I set up the connection as follows:

Serial connection through COM3 (the serial port on my laptop)

Speed: 9600

Data Bits: 8

Stop Bits: 1

No parity or flow control

When I open the connection, I'm met with a blank console screen. Pressing enter or escape doesn't return any response from the Fortigate. 

On the surface here, does anyone have any ideas that spring to mind? Happy to provide more info as needed