Thank you.
There are three dual phaser banks on both the dorsal and ventral saucer for a total of six banks forward or 12-phasers.
The other two "dark" areas (1 port, 1 starboard) are docking ports for shuttle-pods and worker bees.
If you look at the side-view of the ship you can see a pair of rectangular lights at each port (just below the bridge section on the side-view).
If you look at the top-view, the phaser banks are located at the 45-degree, 90-degree, and 135-degree positions with zero/north being the port/top warp nacelle tip (approximately).