Where can the security rooms spawn on The Diamond heist?
According to the Payday 2 wikipedia, the cameraroom can be behind any of the white doors.
The location of the numerous white metal doors remains constant, however, their contents change between attempts:
Doors with a red and white "Employees Only" sign are empty, but can be used to stash bags or evade patrols.
Doors with a orange and black electrical danger sign above them contain an electric box.
Doors with a black and white "Security" sign contain the camera system, a security guard, and the security computer.
http://payday.wikia.com/wiki/The_Diamond