The RobCo sales and service center is a location in the Commonwealth, after the Fallout 4 add-on Automatron is installed.
This unassuming sales and services center for RobCo Industries was actual a front for the United States Army's Robotics Division as a robobrain research and development center, designated "RB-2851". After the war, the compound beneath Eagle Hill, East Boston became the sanctuary of the Mechanist.
The facility opens to a display room of RobCo's latest personal computers, with an "employees only" section in the western corner. Through these doors is a catwalk spanning across the wall of a storeroom. The southwest wall has an Expert-locked door back out into East Boston, while the northeast corner has an access port which is unlocked by an M-SAT modification to a weapon. Through the many hidden door is the Mechanist's Lair.
The RobCo sales and service center appears only in Fallout 4 add-on Automatron.