The PCB of the Sentry 3 is white, and it appears as though there is a lot going on here. In the middle towards the bottom of the PCB you can see the large 3 pin power connector, on the left of the power connector are three 3-pin fan headers. To the right are two 3-pin fan headers. Directly to the right of the power connector is a small 2-pin temperature sensor header.
There are five 4-pin PWM connectors available to use on the Sentry 3. These cables are approximately 12″ long, though extension cables could be daisy chained if you needed a longer cable. According to NZXT each channel can handle 15 watts which means that you could run 3 high performance fans on each channel.