Abstract: An image forming device with one or more door assemblies that engage locking mechanisms to secure a module in an operating position. The module may be coupled to one of the one or more door assemblies. A first locking mechanism may secure the module to the image forming device body when a first door assembly is closed. A second locking mechanism may secure the module to the body with a greater securing force than the first locking mechanism to secure the module to the body. The second locking mechanism may be engaged upon closing a second door assembly. Separate biasing members may be used to apply the securing forces. The locking mechanisms may comprise four-bar or over-center mechanisms to apply the securing forces.